Iron Mountain (IRM) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 29, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	1-13045
Entity Registrant Name	IRON MOUNTAIN INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	23-2588479
Entity Address, Address Line One	One Federal Street
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02110
City Area Code	617
Local Phone Number	535-4766
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	IRM
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Emerging Growth Company	false
Small Business Entity	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		289,549,498
Entity Central Index Key	0001020569
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 161,439	$ 205,063
Accounts receivable (less allowances of $60,214 and $56,981 as of September 30, 2021 and December 31, 2020, respectively)	884,348	859,344
Prepaid expenses and other	223,266	205,380
Total Current Assets	1,269,053	1,269,787
Property, Plant and Equipment:
Property, plant and equipment	8,503,171	8,246,337
Less—Accumulated depreciation	(3,914,553)	(3,743,894)
Property, Plant and Equipment, Net	4,588,618	4,502,443
Other Assets, Net:
Goodwill	4,472,641	4,557,609
Customer relationships, customer inducements and data center lease-based intangibles	1,230,330	1,326,977
Operating lease right-of-use assets	2,308,047	2,196,502
Other	365,706	295,949
Total Other Assets, Net	8,376,724	8,377,037
Total Assets	14,234,395	14,149,267
Current Liabilities:
Current portion of long-term debt	318,144	193,759
Accounts payable	324,210	359,863
Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)	926,360	1,146,288
Deferred revenue	257,593	295,785
Total Current Liabilities	1,826,307	1,995,695
Long-term Debt, net of current portion	8,815,273	8,509,555
Long-term Operating Lease Liabilities, net of current portion	2,164,449	2,044,598
Other Long-term Liabilities	155,048	204,508
Deferred Income Taxes	236,782	198,377
Commitments and Contingencies
Redeemable Noncontrolling Interests	61,390	59,805
Equity:
Preferred stock (par value $0.01; authorized 10,000,000 shares; none issued and outstanding)	0	0
Common stock (par value $0.01; authorized 400,000,000 shares; issued and outstanding 289,546,146 and 288,273,049 shares as of September 30, 2021 and December 31, 2020, respectively)	2,895	2,883
Additional paid-in capital	4,407,253	4,340,078
(Distributions in excess of earnings) Earnings in excess of distributions	(3,101,813)	(2,950,339)
Accumulated other comprehensive items, net	(334,453)	(255,893)
Total Iron Mountain Incorporated Stockholders' Equity	973,882	1,136,729
Noncontrolling Interests	1,264	0
Total Equity	975,146	1,136,729
Total Liabilities and Equity	$ 14,234,395	$ 14,149,267

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 60,214	$ 56,981
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares (in shares)	10,000,000	10,000,000
Preferred stock, issued shares (in shares)	0	0
Preferred stock, outstanding shares (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares (in shares)	400,000,000	400,000,000
Common stock, issued shares (in shares)	289,546,146	288,273,049
Common stock, outstanding shares (in shares)	289,546,146	288,273,049

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenues:
Storage rental	$ 718,614	$ 696,294	$ 2,144,942	$ 2,056,797
Service	411,534	340,353	1,187,002	1,030,820
Total Revenues	1,130,148	1,036,647	3,331,944	3,087,617
Operating Expenses:
Cost of sales (excluding depreciation and amortization)	481,663	434,505	1,408,151	1,308,119
Selling, general and administrative	241,596	232,095	760,098	712,775
Depreciation and amortization	174,818	157,252	507,145	483,686
Acquisition and Integration Costs	1,138	0	3,415	0
Restructuring Charges	50,432	48,371	129,686	128,715
Intangible impairments	0	0	0	23,000
(Gain) Loss on disposal/write-down of property, plant and equipment, net	(935)	(75,840)	(134,321)	(78,170)
Total Operating Expenses	948,712	796,383	2,674,174	2,578,125
Operating Income (Loss)	181,436	240,264	657,770	509,492
Interest Expense, Net (includes Interest Income)	103,809	104,303	313,451	313,408
Other (Income) Expense, Net	(18,501)	83,465	(200,018)	66,439
Net Income (Loss) Before Provision (Benefit) for Income Taxes	96,128	52,496	544,337	129,645
Provision (Benefit) for Income Taxes	28,017	13,934	153,073	33,304
Net Income (Loss)	68,111	38,562	391,264	96,341
Less: Net Income (Loss) Attributable to Noncontrolling Interests	428	168	2,693	1,058
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 67,683	$ 38,394	$ 388,571	$ 95,283
Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated:
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.23	$ 0.13	$ 1.34	$ 0.33
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.23	$ 0.13	$ 1.34	$ 0.33
Weighted Average Common Shares Outstanding-Basic (in shares)	289,762,000	288,403,000	289,255,000	288,105,000
Weighted Average Common Shares Outstanding-Diluted (in shares)	291,482,255	288,810,701	290,696,596	288,471,311

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement [Abstract]
Interest income	$ 2,160	$ 2,476	$ 5,858	$ 6,491

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 68,111	$ 38,562	$ 391,264	$ 96,341
Other Comprehensive (Loss) Income:
Foreign Currency Translation Adjustment	(91,263)	44,883	(115,075)	(109,742)
Change in Fair Value of Derivative Instruments	14,665	(184)	35,505	(11,507)
Total Other Comprehensive (Loss) Income	(76,598)	44,699	(79,570)	(121,249)
Comprehensive (Loss) Income	(8,487)	83,261	311,694	(24,908)
Comprehensive (Loss) Income Attributable to Noncontrolling Interests	(370)	522	1,683	406
Comprehensive (Loss) Income Attributable to Iron Mountain Incorporated	$ (8,117)	$ 82,739	$ 310,011	$ (25,314)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	COMMON STOCK	ADDITIONAL PAID-IN CAPITAL	(DISTRIBUTIONS IN EXCESS OF EARNINGS) EARNINGS IN EXCESS OF DISTRIBUTIONS	ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET	NONCONTROLLING INTERESTS	REDEEMABLE NONCONTROLLING INTERESTS
Beginning of Period at Dec. 31, 2019	$ 1,464,227	$ 2,873	$ 4,298,566	$ (2,574,896)	$ (262,581)	$ 265
Balance (in shares) at Dec. 31, 2019		287,299,645
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	34,639	$ 9	34,630
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		863,321
Change in equity related to redeemable noncontrolling interests	2,603		2,603				$ (2,603)
Parent cash dividends declared	(538,531)			(538,531)
Foreign currency translation adjustment	(109,090)				(109,090)
Change in fair value of derivative instruments	(11,507)				(11,507)
Net income (loss)	94,905			95,283		(378)
End of period at Sep. 30, 2020	937,246	$ 2,882	4,335,799	(3,018,144)	(383,178)	(113)
Balance (in shares) at Sep. 30, 2020		288,162,966
Beginning of redeemable noncontrolling interest at Dec. 31, 2019							67,682
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests	2,603		2,603				(2,603)
Foreign currency translation adjustment							(652)
Net income (loss)							1,436
Noncontrolling interests dividends							(2,197)
Ending of redeemable noncontrolling interest at Sep. 30, 2020							63,666
Beginning of Period at Jun. 30, 2020	1,024,331	$ 2,881	4,325,803	(2,876,861)	(427,523)	31
Balance (in shares) at Jun. 30, 2020		288,142,703
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	9,997	$ 1	9,996
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		20,263
Parent cash dividends declared	(179,677)			(179,677)
Foreign currency translation adjustment	44,529				44,529
Change in fair value of derivative instruments	(184)				(184)
Net income (loss)	38,250			38,394		(144)
End of period at Sep. 30, 2020	937,246	$ 2,882	4,335,799	(3,018,144)	(383,178)	(113)
Balance (in shares) at Sep. 30, 2020		288,162,966
Beginning of redeemable noncontrolling interest at Jun. 30, 2020							63,512
Increase (Decrease) in Temporary Equity [Roll Forward]
Foreign currency translation adjustment							354
Net income (loss)							312
Noncontrolling interests dividends							(512)
Ending of redeemable noncontrolling interest at Sep. 30, 2020							63,666
Beginning of Period at Dec. 31, 2020	$ 1,136,729	$ 2,883	4,340,078	(2,950,339)	(255,893)	0
Balance (in shares) at Dec. 31, 2020	288,273,049	288,273,049
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	$ 66,507	$ 12	66,495
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		1,273,097
Change in equity related to redeemable noncontrolling interests	680		680				(512)
Parent cash dividends declared	(540,045)			(540,045)
Foreign currency translation adjustment	(114,112)				(114,065)
Change in fair value of derivative instruments	35,505				35,505
Net income (loss)	388,571			388,571		0
End of period at Sep. 30, 2021	$ 975,146	$ 2,895	4,407,253	(3,101,813)	(334,453)	1,264
Balance (in shares) at Sep. 30, 2021	289,546,146	289,546,146
Beginning of redeemable noncontrolling interest at Dec. 31, 2020	$ 59,805						59,805
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests	680		680				(512)
Foreign currency translation adjustment						(47)	(963)
Net income (loss)							2,693
Noncontrolling interests equity contributions							2,200
Noncontrolling interests dividends							(1,882)
Purchase of noncontrolling interests	1,311					1,311	2,567
Redemption of noncontrolling interests							(2,518)
Ending of redeemable noncontrolling interest at Sep. 30, 2021	61,390						61,390
Beginning of Period at Jun. 30, 2021	1,147,742	$ 2,895	4,392,396	(2,988,896)	(258,653)	0
Balance (in shares) at Jun. 30, 2021		289,458,768
Increase (Decrease) in Stockholders' Equity
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation	14,857	$ 0	14,857
Issuance of shares under employee stock purchase plan and option plans and stock-based compensation (in shares)		87,378
Change in equity related to redeemable noncontrolling interests							168
Parent cash dividends declared	(180,600)			(180,600)
Foreign currency translation adjustment	(90,512)				(90,465)
Change in fair value of derivative instruments	14,665				14,665
Net income (loss)	67,683			67,683
End of period at Sep. 30, 2021	$ 975,146	$ 2,895	$ 4,407,253	$ (3,101,813)	$ (334,453)	1,264
Balance (in shares) at Sep. 30, 2021	289,546,146	289,546,146
Beginning of redeemable noncontrolling interest at Jun. 30, 2021							64,660
Increase (Decrease) in Temporary Equity [Roll Forward]
Change in equity related to redeemable noncontrolling interests							168
Foreign currency translation adjustment						(47)	(751)
Net income (loss)							428
Noncontrolling interests dividends							(597)
Purchase of noncontrolling interests	$ 1,311					$ 1,311
Redemption of noncontrolling interests							(2,518)
Ending of redeemable noncontrolling interest at Sep. 30, 2021	$ 61,390						$ 61,390

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ 391,264	$ 96,341
Adjustments to reconcile net income (loss) to cash flows from operating activities:
Depreciation	347,269	334,780
Amortization (includes amortization of deferred financing costs and discounts of $12,470 and $13,150 for the nine months ended September 30, 2021 and 2020, respectively)	172,346	162,057
Intangible impairments	0	23,000
Revenue reduction associated with amortization of customer inducements and above- and below-market leases	6,578	7,612
Stock-based compensation expense	46,852	35,618
Provision (benefit) for deferred income taxes	36,333	(3,074)
Loss on early extinguishment of debt	0	68,300
Gain on IPM Divestment (as defined in Note 4)	(180,569)	0
(Gain) loss on disposal/write-down of property, plant and equipment, net	(134,321)	(78,170)
Foreign currency transactions and other, net	(13,239)	4,043
(Increase) decrease in assets	(112,753)	(10,219)
(Decrease) increase in liabilities	(96,423)	(13,070)
Cash Flows from Operating Activities	463,337	627,218
Cash Flows from Investing Activities:
Capital expenditures	(418,976)	(309,162)
Cash paid for acquisitions, net of cash acquired	(203,752)	(118,581)
Acquisition of customer relationships	(4,800)	(3,529)
Customer inducements	(5,148)	(8,269)
Contract fulfillment costs and third-party commissions	(43,699)	(30,705)
Investments in joint ventures and other investments	(72,153)	(6,850)
Net proceeds from IPM Divestment	213,878	0
Proceeds from sales of property and equipment and other, net	214,865	116,965
Cash Flows from Investing Activities	(319,785)	(360,131)
Cash Flows from Financing Activities:
Repayment of revolving credit facility, term loan facilities and other debt	(2,622,555)	(7,354,790)
Proceeds from revolving credit facility, term loan facilities and other debt	3,037,476	7,090,842
Early redemption of senior notes, including call premiums	0	(2,942,554)
Net proceeds from sales of senior notes	0	3,465,000
Debt repayment and equity distribution to noncontrolling interests	(1,882)	(2,197)
Repurchase of noncontrolling interest	(75,000)	0
Parent cash dividends	(538,902)	(537,853)
Net proceeds (payments) associated with employee stock-based awards	19,655	(979)
Other, net	3,621	(24,643)
Cash Flows from Financing Activities	(177,587)	(307,174)
Effect of Exchange Rates on Cash and Cash Equivalents	(9,589)	(1,496)
(Decrease) increase in Cash and Cash Equivalents	(43,624)	(41,583)
Cash and Cash Equivalents, including Restricted Cash, Beginning of Period	205,063	193,555
Cash and Cash Equivalents, including Restricted Cash, End of Period	161,439	151,972
Supplemental Information:
Cash Paid for Interest	395,355	357,897
Cash Paid for Income Taxes, Net	96,174	27,430
Non-Cash Investing and Financing Activities:
Financing Leases	40,590	34,889
Accrued Capital Expenditures	60,418	58,175
Fair Value of Investments Applied to Acquisitions	0	27,276
Dividends Payable	$ 189,010	$ 186,699

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Statement of Cash Flows [Abstract]
Deferred financing costs and discount included in Amortization	$ 12,470	$ 13,150

General

General	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	The unaudited condensed consolidated financial statements of Iron Mountain Incorporated, a Delaware corporation (“IMI”), and its subsidiaries (“we” or “us”), have been prepared pursuant to the rules and regulations of the United States Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been omitted pursuant to those rules and regulations, but we believe that the disclosures included herein are adequate to make the information presented not misleading. The interim condensed consolidated financial statements are presented herein and, in the opinion of management, reflect all adjustments of a normal recurring nature necessary for a fair presentation. Interim results are not necessarily indicative of results for a full year. The Condensed Consolidated Financial Statements and Notes thereto, which are included herein, should be read in conjunction with the Consolidated Financial Statements and Notes thereto for the year ended December 31, 2020 included in our Annual Report on Form 10-K filed with the SEC on February 24, 2021 (our “Annual Report”). We have been organized and have operated as a real estate investment trust for United States federal income tax purposes (“REIT”) beginning with our taxable year ended December 31, 2014. In March 2020, the World Health Organization declared a novel strain of coronavirus (“COVID-19”) a pandemic. The preventative and protective actions that governments have ordered, or we or our customers have implemented, have resulted in a period of reduced service operations and business disruption for us, our customers and other third parties with which we do business. The broader impacts of the COVID-19 pandemic on our financial position, results of operations and cash flows, including impacts to the estimates we use in the preparation of our financial statements, remain uncertain and difficult to predict as information continues to evolve, and the severity and duration of the pandemic remains unknown, as is our visibility of its effect on the markets we serve and our customers within those markets.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	A. CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value. B. ACCOUNTS RECEIVABLE We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues. The rollforward of the allowance for doubtful accounts and credit memo reserves for the nine months ended September 30, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 29,996 Allowance for bad debts charged to expense 16,371 Deductions and other (1) (43,134) Balance as of September 30, 2021 $ 60,214 (1) Primarily consists of the issuance of credit memos, the write-off of accounts receivable, allowances associated with businesses acquired and the impact associated with currency translation adjustments. C. LEASES We lease facilities for certain warehouses, data centers and office space. We also have land leases, including those on which certain facilities are located. Operating and financing lease right-of-use assets and lease liabilities as of September 30, 2021 and December 31, 2020 are as follows: DESCRIPTION SEPTEMBER 30, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,308,047 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 307,032 310,534 Liabilities: Current Operating lease liabilities $ 257,884 $ 250,239 Financing lease liabilities (1) 42,442 43,149 Long-term Operating lease liabilities $ 2,164,449 $ 2,044,598 Financing lease liabilities (1) 321,682 323,162 (1) Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Condensed Consolidated Balance Sheets. The components of the lease expense for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, DESCRIPTION 2021 2020 2021 2020 Operating lease cost (1) $ 140,551 $ 122,737 $ 408,312 $ 365,303 Financing lease cost: Depreciation of financing lease right-of-use assets $ 14,006 $ 12,973 $ 39,062 $ 38,495 Interest expense for financing lease liabilities 5,055 4,891 14,940 14,664 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $28,835 and $86,422 for the three and nine months ended September 30, 2021, respectively, and $27,486 and $82,287 for the three and nine months ended September 30, 2020, respectively. Other information: Supplemental cash flow information relating to our leases for the nine months ended September 30, 2021 and 2020 is as follows: NINE MONTHS ENDED SEPTEMBER 30, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 291,535 $ 266,619 Operating cash flows used in financing leases (interest) 14,940 14,664 Financing cash flows used in financing leases 35,360 36,008 NON-CASH ITEMS: Operating lease modifications and reassessments $ 103,158 $ 89,727 New operating leases (including acquisitions and sale-leaseback transactions) 240,822 173,635 D. GOODWILL Our reporting units as of December 31, 2020 are described in detail in Note 2.k. to Notes to Consolidated Financial Statements included in our Annual Report. The goodwill associated with acquisitions completed during the first nine months of 2021 (as described in Note 3) has been incorporated into our reporting units as they existed as of December 31, 2020. The changes in the carrying value of goodwill attributable to each reportable operating segment for the nine months ended September 30, 2021 are as follows: GLOBAL RIM BUSINESS GLOBAL DATA CENTER BUSINESS CORPORATE AND OTHER BUSINESS TOTAL CONSOLIDATED Goodwill balance, net of accumulated amortization as of December 31, 2020 $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Non-tax deductible goodwill acquired during the period 17,180 — 9,991 27,171 Goodwill allocated to IPM Divestment — — (46,105) (46,105) Fair value and other adjustments (6,091) — (1,268) (7,359) Currency effects (49,737) (7,995) (943) (58,675) Goodwill balance, net accumulated amortization as of September 30, 2021 $ 3,985,534 $ 428,992 $ 58,115 $ 4,472,641 Accumulated goodwill impairment balance as of September 30, 2021 $ 132,409 $ — $ 26,011 $ 158,420 E. INVESTMENTS 2021 NEWLY FORMED JOINT VENTURE In April 2021, we closed on an agreement to form a joint venture (the "Web Werks JV") with the shareholders of Web Werks India Private Limited ("Web Werks"), a colocation data center provider in India. In connection with the formation of the Web Werks JV, we made an initial investment of approximately 3,750,000 Indian rupees (or approximately $50,100, based upon the exchange rate between the United States dollar and Indian rupee as of the closing date of the initial investment) in exchange for a noncontrolling interest in the form of convertible preference shares in the Web Werks JV (the “Initial Web Werks JV Investment”). These shares are convertible into a to-be-determined amount of common shares based upon the achievement of EBITDA targets for the Web Werks JV's fiscal year ending March 31, 2022. Under the terms of the Web Werks JV shareholder agreement, we are required to make additional investments over a period ending May 2023 totaling approximately 7,500,000 Indian rupees (or approximately $100,000, based upon the current exchange rate between the United States dollar and Indian rupee). JOINT VENTURE SUMMARY The following joint ventures are accounted for as equity method investments and are presented as a component of Other within Other assets, net in our Condensed Consolidated Balance Sheets. The carrying values and equity interests in our joint ventures at September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 CARRYING VALUE EQUITY INTEREST CARRYING VALUE EQUITY INTEREST Web Werks JV $ 51,257 38 % $ — — % Joint venture with AGC Equity Partners (the “Frankfurt JV”) 26,272 20 % 26,500 20 % Joint venture with MakeSpace Labs, Inc. (the “MakeSpace JV”) 27,419 48 % 16,924 39 % F. FAIR VALUE MEASUREMENTS The assets and liabilities carried at fair value measured on a recurring basis as of September 30, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT SEPTEMBER 30, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 9,186 $ — $ 9,186 $ — Time Deposits 2,175 — 2,175 — Trading Securities 11,713 11,572 141 — Derivative Assets 1,214 — 1,214 — Derivative Liabilities 15,412 — 15,412 — FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2020 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 62,657 $ — $ 62,657 $ — Time Deposits 2,121 — 2,121 — Trading Securities 10,892 10,636 256 — Derivative Liabilities 49,703 — 49,703 — There were no material items that are measured at fair value on a non-recurring basis at September 30, 2021 and December 31, 2020, other than (i) those disclosed in Note 2.o. to Notes to Consolidated Financial Statements included in our Annual Report, (ii) our investment in the Web Werks JV, as described in Note 2.e., and (iii) those acquired in acquisitions that occurred during the nine months ended September 30, 2021, as described in Note 3, all of which are based on Level 3 inputs. G. REDEEMABLE NONCONTROLLING INTERESTS In 2018, one of the noncontrolling interest shareholders in one of our foreign consolidated subsidiaries exercised its option to put its ownership interest back to us. Upon the exercise of the put option, this noncontrolling interest became mandatorily redeemable by us, and, therefore, was accounted for as a liability rather than a component of redeemable noncontrolling interests. In May 2021, we agreed to final settlement terms and paid the put option price for the noncontrolling interest shares. We remain in dispute with this former shareholder with respect to whether interest from the date of the put and certain other costs should be reimbursable. We have vigorously defended that interest and costs are not owed, and are currently awaiting a ruling from an arbitration hearing. H. ACCUMULATED OTHER COMPREHENSIVE ITEMS, NET The changes in accumulated other comprehensive items, net for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, 2021 NINE MONTHS ENDED SEPTEMBER 30, 2021 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (229,790) $ (28,863) $ (258,653) $ (206,190) $ (49,703) $ (255,893) Other comprehensive (loss) income): Foreign currency translation and other adjustments (90,465) — (90,465) (114,065) — (114,065) Change in fair value of derivative instruments — 14,665 14,665 — 35,505 35,505 Total other comprehensive (loss) income (90,465) 14,665 (75,800) (114,065) 35,505 (78,560) End of Period $ (320,255) $ (14,198) $ (334,453) $ (320,255) $ (14,198) $ (334,453) THREE MONTHS ENDED SEPTEMBER 30, 2020 NINE MONTHS ENDED SEPTEMBER 30, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (406,444) $ (21,079) $ (427,523) $ (252,825) $ (9,756) $ (262,581) Other comprehensive income (loss): Foreign currency translation and other adjustments 44,529 — 44,529 (109,090) — (109,090) Change in fair value of derivative instruments — (184) (184) — (11,507) (11,507) Total other comprehensive income (loss) 44,529 (184) 44,345 (109,090) (11,507) (120,597) End of Period $ (361,915) $ (21,263) $ (383,178) $ (361,915) $ (21,263) $ (383,178) I. REVENUES The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (collectively, “Contract Fulfillment Costs”). Contract Fulfillment Costs as of September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 71,540 $ (41,246) $ 30,294 $ 63,721 $ (33,352) $ 30,369 Commissions asset 107,298 (48,708) 58,590 91,069 (38,787) 52,282 Deferred revenue liabilities are reflected in our Condensed Consolidated Balance Sheets as follows: DESCRIPTION LOCATION IN BALANCE SHEET SEPTEMBER 30, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 257,593 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 34,342 35,612 DATA CENTER LESSOR CONSIDERATIONS Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842) , as amended. Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Storage rental revenue (1) $ 72,411 $ 68,416 $ 210,805 $ 196,823 (1) Revenue associated with power and connectivity included within storage rental revenue was $14,639 and $42,333 for the three and nine months ended September 30, 2021, respectively, and $12,033 and $34,986 for the three and nine months ended September 30, 2020, respectively. J. STOCK-BASED COMPENSATION PLAN AMENDMENTS In May 2021, our stockholders (1) approved an amendment to the Iron Mountain Incorporated 2014 Stock and Cash Incentive Plan (the “2014 Plan”) to (i) increase the number of shares of our common stock authorized for issuance thereunder by 8,000,000 from 12,750,000 to 20,750,000, (ii) extend the termination date of the 2014 Plan from May 24, 2027 to May 12, 2031, (iii) provide that, other than in specified circumstances, no equity-based award will vest before the first anniversary of the date of grant and (iv) provide that dividends and dividend equivalents are not paid with respect to stock options or stock appreciation rights and (2) approved an amendment to the Iron Mountain Incorporated 2013 Employee Stock Purchase Plan to increase the number of shares of Common Stock authorized for issuance thereunder by 1,000,000 from 1,000,000 to 2,000,000. STOCK-BASED COMPENSATION EXPENSE Stock-based compensation expense for the cost of stock options, restricted stock units (“RSUs”), performance units (“PUs”) and shares of stock issued under our employee stock purchase plan (collectively, “Employee Stock-Based Awards”) for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Stock-based compensation expense $ 13,200 $ 8,946 $ 46,852 $ 35,618 As of September 30, 2021, unrecognized compensation cost related to the unvested portion of our Employee Stock-Based Awards is $48,494. RESTRICTED STOCK UNITS AND PERFORMANCE UNITS The fair value of RSUs and earned PUs that vested during the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Fair value of RSUs vested $ 8,425 $ 2,766 $ 31,404 $ 24,411 Fair value of earned PUs that vested 22,030 1,370 27,856 12,421 As of September 30, 2021, we expected 133%, 114% and 103% achievement of each of the predefined targets associated with the awards of PUs made in 2021, 2020 and 2019, respectively. K. ACQUISITION AND INTEGRATION COSTS Acquisition and integration costs represent operating expenditures directly associated with the closing and integration activities of our business acquisitions that have closed, or are highly probable of closing, and include (i) advisory, legal and professional fees to complete business acquisitions and (ii) costs to integrate acquired businesses into our existing operations, including move, severance, facility upgrade and system integration costs (collectively, "Acquisition and Integration Costs"). Acquisition and Integration Costs do not include costs associated with the formation of joint ventures or costs associated with the acquisition of customer relationships. Total Acquisition and Integration Costs for the three and nine months ended September 30, 2021 is $1,138 and $3,415, respectively. L. (GAIN) LOSS ON DISPOSAL/WRITE-DOWN OF PROPERTY, PLANT AND EQUIPMENT, NET Consolidated (gain) loss on disposal/write-down of property, plant and equipment, net for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 (1) 2021 (2) 2020 (1) (Gain) Loss on disposal/write-down of property, plant and equipment, net (3) $ (935) $ (75,840) $ (134,321) $ (78,170) (1) The gains for both the three and nine months ended September 30, 2020 primarily consisted of gains of approximately $76,400 associated with the sale-leaseback transactions of two facilities in the United States. (2) The gains for the nine months ended September 30, 2021 primarily consisted of gains of approximately $127,400 associated with the sale-leaseback transactions of five facilities in the United Kingdom, which occurred during the second quarter of 2021. M. OTHER (INCOME) EXPENSE, NET Consolidated other (income) expense, net for the three and nine months ended September 30, 2021 and 2020 consists of the following: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED DESCRIPTION 2021 2020 2021 2020 Foreign currency transaction (gains) losses, net $ (23,200) $ 29,635 $ (16,157) $ (6,293) Debt extinguishment expense — 51,260 — 68,300 Other, net (1) 4,699 2,570 (183,861) 4,432 Other (Income) Expense, Net $ (18,501) $ 83,465 $ (200,018) $ 66,439 (1) Other, net for the nine months ended September 30, 2021 is primarily comprised of (a) a gain of approximately $180,600 associated with our IPM Divestment and (b) a gain of approximately $20,300 associated with the loss of control and related deconsolidation, as of May 18, 2021, of one of our wholly owned Netherlands subsidiaries, for which we had value-added tax liability exposure that was recorded in 2019. N. INCOME TAXES We provide for income taxes during interim periods based on our estimate of the effective tax rate for the year. Our effective tax rates for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Effective Tax Rate (1) 29.1 % 26.5 % 28.1 % 25.7 % (1) The primary reconciling items between the federal statutory tax rate of 21.0% and our overall effective tax rate for the three and nine months ended September 30, 2021 and 2020 were the impacts of differences in the tax rates at which our foreign earnings are subject, partially offset by the benefits derived from the dividends paid deduction. The costs associated with Project Summit (as defined in Note 11) are more heavily weighted to our United States qualified REIT subsidiaries ("QRSs"), and, therefore, provide no tax benefit. Additionally, the nine months ended September 30, 2021, reflects a discrete tax expense of approximately $12,000 primarily resulting from a tax law change in the United Kingdom. At December 31, 2020, we concluded that it was our intent to indefinitely reinvest our current and future undistributed earnings of certain of our unconverted foreign taxable REIT subsidiaries (“TRSs”) outside the United States, with the exception of certain limited instances. During 2021, as a result of the enactment of a tax law and the closing of various acquisitions, we reassessed this intention and concluded that it is no longer our intention to reinvest our undistributed earnings of our foreign TRSs indefinitely outside the United States. As a REIT, future repatriation of incremental undistributed earnings of our foreign subsidiaries will not be subject to federal or state income tax, with the exception of foreign withholding taxes. However, such future repatriations may require distributions to our stockholders in accordance with REIT distribution rules, and any such distribution may then be taxable, as appropriate, at the stockholder level. We expect to provide for foreign withholding taxes on the current and future earnings of all of our foreign subsidiaries as the result of such reassessment. O. INCOME (LOSS) PER SHARE—BASIC AND DILUTED The calculation of basic and diluted income (loss) per share for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 68,111 $ 38,562 $ 391,264 $ 96,341 Less: Net Income (Loss) Attributable to Noncontrolling Interests 428 168 2,693 1,058 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 67,683 $ 38,394 $ 388,571 $ 95,283 Weighted-average shares—basic 289,762,000 288,403,000 289,255,000 288,105,000 Effect of dilutive potential stock options 869,600 14,758 522,642 28,723 Effect of dilutive potential RSUs and PUs 850,655 392,943 918,954 337,588 Weighted-average shares—diluted 291,482,255 288,810,701 290,696,596 288,471,311 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.23 $ 0.13 $ 1.34 $ 0.33 Diluted $ 0.23 $ 0.13 $ 1.34 $ 0.33 Antidilutive stock options, RSUs and PUs, excluded from the calculation 351,673 5,529,126 1,813,880 5,959,693 P. RECENT ACCOUNTING PRONOUNCEMENTS In December 2019, the Financial Accounting Standards Board issued ASU No. 2019-12, Income Taxes (Topic 740) (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. ASU 2019-12 also adds guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. We adopted ASU 2019-12 on January 1, 2021. ASU 2019-12 did not have a material impact on our consolidated financial statements.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Acquisitions	ACQUISITIONS INFOFORT ACQUISITION On September 15, 2021, in order to further expand our records management operations in the Middle East and North Africa, we acquired Information Fort, LLC, a records and information management provider, for approximately $90,300. FRANKFURT DATA CENTER ACQUISITION On September 23, 2021, in order to further enhance our data center operations in Germany, we acquired a Frankfurt data center for approximately 77,900 Euros (or approximately $91,300, based upon the exchange rate between the Euro and the United States dollar on the closing date of this acquisition). OTHER 2021 ACQUISITIONS In addition to the transactions noted above, during the nine months ended September 30, 2021, in order to enhance our existing operations in the United Kingdom and Indonesia and to expand our operations into Morocco, we completed the acquisition of two records management companies and one art storage company for total cash consideration of approximately $45,100. PURCHASE PRICE ALLOCATION A summary of the cumulative consideration paid and the preliminary allocation of the purchase price paid for all of our 2021 acquisitions through September 30, 2021 is as follows: NINE MONTHS ENDED SEPTEMBER 30, 2021 Cash Paid (gross of cash acquired) $ 224,192 Fair Value of Noncontrolling Interests 3,878 Purchase Price Holdbacks and Other 2,534 Total Consideration 230,604 Fair Value of Identifiable Assets Acquired and Liabilities Assumed: Cash 20,440 Accounts Receivable, Prepaid Expenses and Other Assets 25,392 Property, Plant and Equipment (1) 147,132 Customer Relationship Intangible Assets (2) 39,315 Operating Lease Right-of-Use Assets 45,209 Data Center In-Place Leases (3) 4,994 Data Center Tenant Relationships (4) 4,682 Data Center Above-Market Leases (5) 1,042 Debt Assumed (9,026) Accounts Payable, Accrued Expenses and Other Liabilities (23,082) Operating Lease Liabilities (45,209) Deferred Income Taxes (7,436) Data Center Below-Market Leases (5) (20) Total Fair Value of Identifiable Net Assets Acquired 203,433 Goodwill Initially Recorded $ 27,171 (1) Consists primarily of land and building. (2) The preliminary weighted average lives of customer relationship intangible assets associated with acquisitions is 9 years. (3) The preliminary weighted average lives of data center in-place leases associated with acquisitions is 5 years. (4) The preliminary weighted average lives of data center tenant relationships associated with acquisitions is 5 years. (5) The preliminary weighted average lives of data center above-market leases associated with acquisitions is 5 years and the weighted average lives of data center below-market leases associated with acquisitions is 4 years. The preliminary purchase price allocations that are not finalized as of September 30, 2021 relate to the final assessment of the fair values of intangible assets (primarily customer relationship intangible assets) and property, plant and equipment associated with the acquisitions we closed in 2021. Any adjustments to our estimates of purchase price allocation will be made in the periods in which the adjustments are determined, but no later than the one year measurement period, and the cumulative effect of such adjustments will be calculated as if the adjustments had been completed as of the acquisition dates. Adjustments recorded during the nine months ended September 30, 2021 were not material to our results from operations.

Divestments

Divestments	9 Months Ended
	Sep. 30, 2021
Discontinued Operations and Disposal Groups [Abstract]
Divestments	On June 7, 2021, we sold our Intellectual Property Management ("IPM") business, also known as our technology escrow services business, which we predominantly operated in the United States, for total gross consideration of approximately $216,600 (the “IPM Divestment”). As a result of the IPM Divestment, we recorded a gain on sale of approximately $180,600 to Other (income) expense, net, during the nine months ended September 30, 2021, the substantial majority of which was recorded during the second quarter of 2021, representing the excess of the fair value of the consideration received over the sum of the carrying value of the IPM business. We have concluded that the IPM Divestment does not meet the criteria to be reported as discontinued operations in our consolidated financial statements, as our decision to divest this business does not represent a strategic shift that will have a major effect on our operations and financial results. Accordingly, the revenues and expenses associated with this business are presented as a component of operating income (loss) in our Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2021 and 2020 through the closing date of the IPM Divestment and the cash flows associated with this business is presented as a component of cash flows from operations in our Condensed Consolidated Statements of Cash Flows for the nine months ended September 30, 2021 and 2020 through the closing date of the IPM Divestment.

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES Derivative instruments we are party to include: (i) interest rate swap agreements (which are designated as cash flow hedges) and (ii) cross-currency swap agreements (which are designated as net investment hedges). INTEREST RATE SWAP AGREEMENTS DESIGNATED AS CASH FLOW HEDGES In March 2018, we entered into interest rate swap agreements to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness. As of September 30, 2021 and December 31, 2020, we had $350,000 in notional value of interest rate swap agreements outstanding, which expire in March 2022. Under the interest rate swap agreements, we receive variable rate interest payments associated with the notional amount of each interest rate swap, based upon one-month LIBOR, in exchange for the payment of fixed interest rates as specified in the interest rate swap agreements. In July 2019, we entered into forward-starting interest rate swap agreements to limit our exposure to changes in interest rates on a portion of our floating rate indebtedness once our current interest rate swap agreements expire in March 2022. The forward-starting interest rate swap agreements have $350,000 in notional value, commence in March 2022 and expire in March 2024. Under the forward-starting interest rate swap agreements, we will receive variable rate interest payments based upon one-month LIBOR, in exchange for the payment of fixed interest rates as specified in the interest rate swap agreements. We have designated these interest rate swap agreements, including the forward-starting interest rate swap agreements, as cash flow hedges. Unrealized gains are recognized as assets, while unrealized losses are recognized as liabilities. CROSS-CURRENCY SWAP AGREEMENTS DESIGNATED AS A HEDGE OF NET INVESTMENT In August 2019, we entered into cross-currency swap agreements to hedge the variability of exchange rate impacts between the United States dollar and the Euro. Under the terms of the cross-currency swap agreements, we notionally exchanged approximately $110,000 at an interest rate of 6.0% for approximately 99,055 Euros at a weighted average interest rate of approximately 3.65%. These cross-currency swap agreements expire in August 2023 (“August 2023 Cross-Currency Swap Agreements”). In September 2020, we entered into cross-currency swap agreements to hedge the variability of exchange rate impacts between the United States dollar and the Euro. Under the terms of the cross-currency swap agreements, we notionally exchanged approximately $359,200 at an interest rate of 4.5% for approximately 300,000 Euros at a weighted average interest rate of approximately 3.4%. These cross-currency swap agreements expire in February 2026 (“February 2026 Cross-Currency Swap Agreements”). We have designated these cross-currency swap agreements as a hedge of net investment against certain of our Euro denominated subsidiaries and they require an exchange of the notional amounts at maturity. These cross-currency swap agreements are marked to market at each reporting period, representing the fair values of the cross-currency swap agreements, and any changes in fair value are recognized as a component of Accumulated other comprehensive items, net. Unrealized gains are recognized as assets while unrealized losses are recognized as liabilities. (Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at September 30, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) SEPTEMBER 30, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (13,116) $ (21,062) Net Investment Hedges (3) August 2023 Cross-Currency Swap Agreements $ (2,296) $ (8,229) February 2026 Cross-Currency Swap Agreements 1,214 (20,412) (1) Our derivative assets are included as a component of Other assets in our Condensed Consolidated Balance Sheets and our derivative liabilities are included either as a component of (i) Accrued expenses and other current liabilities or (ii) Other long-term liabilities in our Condensed Consolidated Balance Sheets. As of September 30, 2021, $1,214 is included within Other assets, $4,296 is included within Accrued expenses and other current liabilities and $11,116 is included within Other long-term liabilities. As of December 31, 2020, $49,703 is included within Other long-term liabilities. (2) As of September 30, 2021, cumulative net losses of $13,116 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of September 30, 2021, cumulative net losses of $1,082 are recorded within Accumulated other comprehensive items, net associated with these cross-currency swap agreements. Unrealized gains (losses) recognized during the three and nine months ended September 30, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, DERIVATIVE INSTRUMENTS (1) 2021 2020 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 1,950 $ 1,185 $ 7,946 $ (14,445) Net Investment Hedges August 2023 Cross-Currency Swap Agreements $ 2,655 $ (5,716) $ 5,933 $ (1,408) February 2026 Cross-Currency Swap Agreements 10,060 4,346 21,626 4,346 (1) These amounts are recognized as unrealized gains (losses), a component of Accumulated other comprehensive items, net. EURO NOTES DESIGNATED AS A HEDGE OF NET INVESTMENT Prior to their redemption in August 2020, we designated a portion of our previously outstanding 3% Euro Senior Notes due 2025 (the “Euro Notes”) as a hedge of net investment of certain of our Euro denominated subsidiaries. From January 1, 2020 through March 31, 2020, we designated 300,000 Euros of our Euro Notes as a hedge of net investment of certain of our Euro denominated subsidiaries. As a result, we recorded foreign exchange (gains) losses related to the change in fair value of such debt due to currency translation adjustments as a component of Accumulated other comprehensive items, net. Foreign exchange gains (losses) associated with this hedge of net investment for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 (1) 2020 2021 (1) 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ (16,604) $ — $ (17,005) (1) As there are no hedges of net investment outstanding during the three and nine months ended September 30, 2021, no foreign exchange gains (losses) associated with hedges of net investment have been recognized. As of September 30, 2021, cumulative net gains of $3,256, net of tax, are recorded in Accumulated other comprehensive items, net associated with this net investment hedge.

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	Long-term debt is as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE Revolving Credit Facility (1) $ 310,000 $ (6,034) $ 303,966 $ 310,000 $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 206,250 — 206,250 206,250 215,625 — 215,625 215,625 Term Loan B 674,540 (5,308) 669,232 675,500 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) (2) 223,109 (881) 222,228 223,557 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 188,431 (874) 187,557 188,431 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 538,374 (4,151) 534,223 544,431 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (3) 1,000,000 (8,532) 991,468 1,035,000 1,000,000 (9,598) 990,402 1,046,250 5 1 / 4 % Senior Notes due 2028 (the “5 1 / 4 % Notes due 2028”) (3) 825,000 (7,676) 817,324 861,094 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (3) 500,000 (4,944) 495,056 521,250 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (3) 1,000,000 (11,573) 988,427 1,047,500 1,000,000 (12,658) 987,342 1,050,000 5 1 / 4 % Senior Notes due 2030 (the “5 1 / 4 Notes due 2030”) (3) 1,300,000 (13,287) 1,286,713 1,376,375 1,300,000 (14,416) 1,285,584 1,400,750 4 1 / 2 % Senior Notes due 2031 (the “4 1 / 2 % Notes”) (3) 1,100,000 (11,715) 1,088,285 1,111,000 1,100,000 (12,648) 1,087,352 1,138,500 5 5 / 8 % Senior Notes due 2032 (the “5 5 / 8 % Notes”) (3) 600,000 (6,292) 593,708 642,000 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 483,934 (905) 483,029 483,934 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program 266,400 (449) 265,951 266,400 85,000 (152) 84,848 85,000 Total Long-term Debt 9,216,038 (82,621) 9,133,417 8,797,424 (94,110) 8,703,314 Less Current Portion (319,025) 881 (318,144) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,897,013 $ (81,740) $ 8,815,273 $ 8,603,665 $ (94,110) $ 8,509,555 (1) Collectively, the “Credit Agreement”. The Credit Agreement consists of a revolving credit facility (the “Revolving Credit Facility”) and a term loan (the “Term Loan A”). The Credit Agreement is scheduled to mature on June 3, 2023. In addition, we also had various outstanding letters of credit totaling $3,064. The remaining amount available for borrowing under the Revolving Credit Facility as of September 30, 2021 was $1,436,936 (which amount represents the maximum availability as of such date). The average interest rate in effect under the Credit Agreement was 1.8% and 1.9% as of September 30, 2021 and December 31, 2020, respectively. (2) The AUD Term Loan is scheduled to mature on September 22, 2022, at which point all obligations become due. The full amount of the AUD Term Loan is classified within the current portion of long-term debt in our Condensed Consolidated Balance Sheet as of September 30, 2021. (3) Collectively, the “Parent Notes”. See Note 6 to Notes to Consolidated Financial Statements included in our Annual Report for additional information regarding the Credit Agreement and our other long-term debt, including the direct obligors of each of our debt instruments as well as information regarding the fair value of our debt instruments (including the levels of the fair value hierarchy used to determine the fair value of our debt instruments). The levels of the fair value hierarchy used to determine the fair value of our debt as of September 30, 2021 are consistent with the levels of the fair value hierarchy used to determine the fair value of our debt as of December 31, 2020 (which are disclosed in our Annual Report). UK BILATERAL REVOLVING CREDIT FACILITY On May 25, 2021, Iron Mountain (UK) PLC and Iron Mountain (UK) Data Centre Limited (collectively, the "UK Borrowers") entered into an amendment to the UK Bilateral Facility with Barclays Bank PLC to (i) modify the interest rate from LIBOR plus 2.25% to LIBOR plus 2.0% (with flexibility built in for the expected transition away from LIBOR) and (ii) add an additional option to extend the maturity date by one year. After this amendment, the UK Bilateral Facility contains two one one MAXIMUM AMOUNT £140,000 OPTIONAL ADDITIONAL COMMITMENTS £125,000 INTEREST RATE 2.1% As of September 30, 2021 ACCOUNTS RECEIVABLE SECURITIZATION PROGRAM On June 28, 2021, we entered into an amendment to the Accounts Receivable Securitization Program to extend the maturity date from July 30, 2021 to July 1, 2023, at which point all obligations become due. The interest rate under the amended Accounts Receivable Securitization Program is LIBOR plus 1.0%. The full amount outstanding under the Accounts Receivable Securitization Program is classified within long-term debt, net of current portion at September 30, 2021 and within current portion of long-term debt at December 31, 2020 in our Condensed Consolidated Balance Sheets. There were no other changes to the terms of the Accounts Receivable Securitization Program described in Note 6 to Notes to Consolidated Financial Statements included in our Annual Report. OUTSTANDING BORROWINGS $266,400 INTEREST RATE 1.1% As of September 30, 2021 CASH POOLING During the third quarter of 2021, certain of our subsidiaries in the Asia Pacific region began to participate in two cash pooling arrangements with JP Morgan Chase Bank, N.A. (“JPM”), one of which we utilize to manage global liquidity requirements for our QRSs in the Asia Pacific region (the “JPM QRS Cash Pool") and the other for our TRSs in the Asia Pacific region (the "JPM TRS Cash Pool") (collectively, the “JPM Cash Pools”). Under the JPM Cash Pools, cash deposited by participating subsidiaries with JPM is pledged as security against the debit balances of other participating subsidiaries, and legal rights of offset are provided and, therefore, amounts are presented in our Condensed Consolidated Balance Sheets on a net basis. Each subsidiary receives interest on the cash balances held on deposit or pays interest on its debit balances based on an applicable rate as defined in the JPM Cash Pools. We have executed overdraft facility agreements for the JPM QRS Cash Pool and the JPM TRS Cash Pool in amounts not to exceed $12,000 and $10,000, respectively. Each overdraft facility permits us to cover a temporary net debit position in the applicable pool. In addition to the JPM Cash Pools, we also utilize two separate cash pooling arrangements with Bank Mendes Gans ("BMG"), one of which we utilize to manage global liquidity requirements for our QRSs (the “BMG QRS Cash Pool”) and the other for our TRSs (the “BMG TRS Cash Pool”), each as described in more detail in Note 6 to Notes to Consolidated Financial Statements included in our Annual Report. The approximate amount of the net cash position for our cash pools and the approximate amount of the gross position and outstanding debit balances for each of these pools as of September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION BMG QRS Cash Pool $ 566,100 $ (562,400) $ 3,700 $ 448,700 $ (447,400) $ 1,300 BMG TRS Cash Pool 579,300 (578,300) 1,000 555,500 (553,500) 2,000 JPM QRS Cash Pool 4,200 (2,300) 1,900 — — — JPM TRS Cash Pool 5,200 (4,700) 500 — — — The net cash position balances as of September 30, 2021 and December 31, 2020 are reflected as cash and cash equivalents in our Condensed Consolidated Balance Sheets. LETTERS OF CREDIT As of September 30, 2021, we had outstanding letters of credit totaling $36,506, of which $3,064 reduce our borrowing capacity under the Revolving Credit Facility (as described above). The letters of credit expire at various dates between October 2021 and March 2025. DEBT COVENANTS The Credit Agreement, our bond indentures and other agreements governing our indebtedness contain certain restrictive financial and operating covenants, including covenants that restrict our ability to complete acquisitions, pay cash dividends, incur indebtedness, make investments, sell assets and take other specified corporate actions. The covenants do not contain a rating trigger. Therefore, a change in our debt rating would not trigger a default under the Credit Agreement, our bond indentures or other agreements governing our indebtedness. The Credit Agreement requires that we satisfy a fixed charge coverage ratio, a net total lease adjusted leverage ratio and a net secured debt lease adjusted leverage ratio on a quarterly basis and our bond indentures require that, among other things, we satisfy a leverage ratio (not lease adjusted) or a fixed charge coverage ratio (not lease adjusted), as a condition to taking actions such as paying dividends and incurring indebtedness. The Credit Agreement uses EBITDAR-based calculations and the bond indentures use EBITDA-based calculations as the primary measures of financial performance for purposes of calculating leverage and fixed charge coverage ratios. The EBITDAR- and EBITDA-based leverage calculations include our consolidated subsidiaries, other than those we have designated as “Unrestricted Subsidiaries” as defined in the Credit Agreement and bond indentures. Generally, the Credit Agreement and the bond indentures use a trailing four fiscal quarter basis for purposes of the relevant calculations and require certain adjustments and exclusions for purposes of those calculations, which make the calculation of financial performance for purposes of those calculations under the Credit Agreement and bond indentures not directly comparable to Adjusted EBITDA as presented herein. We are in compliance with our leverage and fixed charge coverage ratios under the Credit Agreement, our bond indentures and other agreements governing our indebtedness as of September 30, 2021 and December 31, 2020. Noncompliance with these leverage and fixed charge coverage ratios would have a material adverse effect on our financial condition.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES We are involved in litigation from time to time in the ordinary course of business, including litigation arising from damage to customer assets in our facilities caused by fires and other natural disasters. While the outcome of such litigation is inherently uncertain, we do not believe any current litigation will have a material adverse effect on our consolidated financial condition, results of operations or cash flows. We have estimated a reasonably possible range for all loss contingencies and believe it is reasonably possible that we could incur aggregate losses in addition to amounts currently accrued for all matters up to an additional $26,000 over the next several years, of which certain amounts would be covered by insurance or indemnity arrangement.

Stockholders' Equity Matters

Stockholders' Equity Matters	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Stockholders' Equity Matters	In fiscal year 2020 and the nine months ended September 30, 2021, our board of directors declared the following dividends: DECLARATION DATE DIVIDEND RECORD DATE TOTAL PAYMENT DATE February 13, 2020 $ 0.6185 March 16, 2020 $ 178,047 April 6, 2020 May 5, 2020 0.6185 June 15, 2020 178,212 July 2, 2020 August 5, 2020 0.6185 September 15, 2020 178,224 October 2, 2020 November 4, 2020 0.6185 December 15, 2020 178,290 January 6, 2021 February 24, 2021 0.6185 March 15, 2021 178,569 April 6, 2021 May 6, 2021 0.6185 June 15, 2021 179,026 July 6, 2021 August 5, 2021 0.6185 September 15, 2021 179,080 October 6, 2021 On November 4, 2021, we declared a dividend to our stockholders of record as of December 15, 2021 of $0.6185 per share, payable on January 6, 2022.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION Our three reportable operating segments as of December 31, 2020 are described in Note 10 to Notes to Consolidated Financial Statements included in our Annual Report and are as follows: • Global Records and Information Management (“Global RIM”) Business • Global Data Center Business • Corporate and Other Business The operations associated with acquisitions completed during the first nine months of 2021 have been incorporated into our existing reportable operating segments. An analysis of our business segment information and reconciliation to the accompanying Condensed Consolidated Financial Statements for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED NINE MONTHS ENDED 2021 2020 2021 2020 Global RIM Business Total Revenues $ 995,577 $ 921,773 $ 2,955,803 $ 2,755,294 Adjusted EBITDA 442,798 393,883 1,281,668 1,169,671 Global Data Center Business Total Revenues $ 88,587 $ 72,814 $ 236,672 $ 206,939 Adjusted EBITDA 35,097 33,359 98,961 94,812 Corporate and Other Business Total Revenues $ 45,984 $ 42,060 $ 139,469 $ 125,384 Adjusted EBITDA (60,126) (51,230) (176,664) (163,010) Total Consolidated Total Revenues $ 1,130,148 $ 1,036,647 $ 3,331,944 $ 3,087,617 Adjusted EBITDA 417,769 376,012 1,203,965 1,101,473 During the fourth quarter of 2020, we changed our definition of Adjusted EBITDA to (a) exclude stock-based compensation expense and (b) include our share of Adjusted EBITDA from our unconsolidated joint ventures. All prior periods have been recast to conform to these changes. We now define Adjusted EBITDA for each segment as net income (loss) before interest expense, net, provision (benefit) for income taxes, depreciation and amortization (inclusive of our share of Adjusted EBITDA from our unconsolidated joint ventures), and excluding certain items we do not believe to be indicative of our core operating results, specifically: EXCLUDED • Acquisition and Integration Costs • Other (income) expense, net • Restructuring Charges • Stock-based compensation expense • Intangible impairments • COVID-19 Costs (as defined below) • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) Internally, we use Adjusted EBITDA as the basis for evaluating the performance of, and allocated resources to, our operating segments. A reconciliation of Net Income (Loss) to Adjusted EBITDA on a consolidated basis for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED NINE MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 68,111 $ 38,562 $ 391,264 $ 96,341 Add/(Deduct): Interest expense, net 103,809 104,303 313,451 313,408 Provision (benefit) for income taxes 28,017 13,934 153,073 33,304 Depreciation and amortization 174,818 157,252 507,145 483,686 Acquisition and Integration Costs 1,138 — 3,415 — Restructuring Charges 50,432 48,371 129,686 128,715 Intangible impairments — — — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (935) (75,840) (134,321) (78,170) Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures (21,517) 81,190 (209,001) 59,398 Stock-based compensation expense (1) 12,644 8,065 45,913 32,056 COVID-19 Costs (2) — — — 9,285 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,252 175 3,340 450 Adjusted EBITDA $ 417,769 $ 376,012 $ 1,203,965 $ 1,101,473 (1) Stock-based compensation expense related to Project Summit is included within Restructuring Charges for the three and nine months ended September 30, 2021 and 2020. (2) Costs that are incremental and directly attributable to the COVID-19 pandemic which are not expected to recur once the pandemic ends ("COVID-19 Costs"). These costs include the purchase of personal protective equipment for our employees and incremental cleaning costs of our facilities, among other direct costs. Information as to our revenues by product and service lines by segment for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2021 2020 2021 2020 Global RIM Business Records Management (1) $ 767,059 $ 712,182 $ 2,285,000 $ 2,118,767 Data Management (1) 115,261 121,936 351,914 367,093 Information Destruction (1)(2) 113,257 87,655 318,889 269,434 Data Center (1) — — — — Global Data Center Business Records Management (1) $ — $ — $ — $ — Data Management (1) — — — — Information Destruction (1)(2) — — — — Data Center (1) 88,587 72,814 236,672 206,939 Corporate and Other Business Records Management (1) $ 30,453 $ 25,720 $ 91,461 $ 75,675 Data Management (1) 15,531 16,340 48,008 49,709 Information Destruction (1)(2) — — — — Data Center (1) — — — — Total Consolidated Records Management (1) $ 797,512 $ 737,902 $ 2,376,461 $ 2,194,442 Data Management (1) 130,792 138,276 399,922 416,802 Information Destruction (1)(2) 113,257 87,655 318,889 269,434 Data Center (1) 88,587 72,814 236,672 206,939 (1) Each of the offerings within our product and service lines has a component of revenue that is storage rental related and a component that is service revenues, except for information destruction, which does not have a storage rental component. (2) Includes secure shredding services.

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Parties	RELATED PARTIES In October 2020, in connection with the formation of the Frankfurt JV, we entered into agreements whereby we will earn various fees, including property management and construction and development fees, for services we are providing to the Frankfurt JV (the “Frankfurt JV Agreements”). Revenues and expenses associated with the Frankfurt JV Agreements are presented as a component of our Global Data Center Business segment. During the three and nine months ended September 30, 2021, we recognized revenue of approximately $1,200 and $3,100, respectively, associated with the Frankfurt JV Agreements. In March 2019, in connection with the formation of the MakeSpace JV, we entered into a storage and service agreement with the MakeSpace JV to provide certain storage and related services to the MakeSpace JV (the “MakeSpace Agreement”). Revenues and expenses associated with the MakeSpace Agreement are presented as a component of our Global RIM Business segment. We recognized revenue of approximately $9,300 and $24,900 for the three and nine months ended September 30, 2021, respectively, and $8,400 and $22,300 for the three and nine months ended September 30, 2020, respectively, associated with the MakeSpace Agreement.

Project Summit

Project Summit	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
Project Summit	In October 2019, we announced our global program designed to better position us for future growth and achievement of our strategic objectives (“Project Summit”). As a result of the program, we expect to reduce the number of positions at vice president and above by approximately 45%. The total program is expected to reduce our total managerial and administrative workforce by approximately 700 positions by the end of 2021. We have also reduced our services and operations workforce. As of September 30, 2021, we have completed approximately 95% of our planned workforce reductions. The activities associated with Project Summit began in the fourth quarter of 2019 and are expected to be substantially complete by the end of 2021. We estimate that the implementation of Project Summit will result in total operating expenditures (“Restructuring Charges”) of approximately $450,000 that primarily consist of: (1) employee severance costs; (2) internal costs associated with the development and implementation of Project Summit initiatives; (3) professional fees, primarily related to third party consultants who are assisting with the design and execution of various initiatives as well as project management activities and (4) system implementation and data conversion costs. Restructuring Charges included in the accompanying Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2021 and 2020, and from the inception of Project Summit through September 30, 2021, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, FROM THE INCEPTION 2021 2020 2021 2020 Employee severance costs $ 6,797 $ 13,579 $ 14,526 $ 31,229 $ 82,725 Professional fees and other costs 43,635 34,792 115,160 97,486 289,954 Restructuring Charges $ 50,432 $ 48,371 $ 129,686 $ 128,715 $ 372,679 Restructuring Charges by segment for the three and nine months ended September 30, 2021 and 2020, and from the inception of Project Summit through September 30, 2021, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, FROM THE INCEPTION 2021 2020 2021 2020 Global RIM Business $ 11,362 $ 16,183 $ 27,528 $ 37,245 $ 116,568 Global Data Center Business 1,285 296 2,922 986 4,860 Corporate and Other Business 37,785 31,892 99,236 90,484 251,251 Restructuring Charges $ 50,432 $ 48,371 $ 129,686 $ 128,715 $ 372,679 A rollforward of the accrued Restructuring Charges, which is included as a component of Accrued expenses and other current liabilities in our Condensed Consolidated Balance Sheets, from December 31, 2019 through September 30, 2021, is as follows: EMPLOYEE SEVERANCE COSTS PROFESSIONAL FEES AND OTHER TOTAL ACCRUED RESTRUCTURING CHARGES Balance as of December 31, 2019 $ 4,823 $ 12,954 $ 17,777 Amounts accrued 47,349 147,047 194,396 Payments (32,455) (136,222) (168,677) Other, including currency translation adjustments (3,439) (4) (3,443) Balance as of December 31, 2020 16,278 23,775 40,053 Amounts accrued 14,525 115,161 129,686 Payments (20,771) (112,714) (133,485) Other, including currency translation adjustments (939) — (939) Balance as of September 30, 2021 $ 9,093 $ 26,222 $ 35,315

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Cash, Cash Equivalents and Restricted Cash	CASH, CASH EQUIVALENTS AND RESTRICTED CASHCash and cash equivalents include cash on hand and cash invested in highly liquid short-term securities, which have remaining maturities at the date of purchase of less than 90 days. Cash and cash equivalents are carried at cost, which approximates fair value.
Accounts Receivable	ACCOUNTS RECEIVABLE We maintain an allowance for doubtful accounts and a credit memo reserve for estimated losses resulting from the potential inability of our customers to make required payments and potential disputes regarding billing and service issues.
Leases	LEASES We lease facilities for certain warehouses, data centers and office space. We also have land leases, including those on which certain facilities are located.
Revenues	The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (collectively, “Contract Fulfillment Costs”).DATA CENTER LESSOR CONSIDERATIONS Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842)
Income Taxes	INCOME TAXESWe provide for income taxes during interim periods based on our estimate of the effective tax rate for the year.At December 31, 2020, we concluded that it was our intent to indefinitely reinvest our current and future undistributed earnings of certain of our unconverted foreign taxable REIT subsidiaries (“TRSs”) outside the United States, with the exception of certain limited instances. During 2021, as a result of the enactment of a tax law and the closing of various acquisitions, we reassessed this intention and concluded that it is no longer our intention to reinvest our undistributed earnings of our foreign TRSs indefinitely outside the United States. As a REIT, future repatriation of incremental undistributed earnings of our foreign subsidiaries will not be subject to federal or state income tax, with the exception of foreign withholding taxes. However, such future repatriations may require distributions to our stockholders in accordance with REIT distribution rules, and any such distribution may then be taxable, as appropriate, at the stockholder level. We expect to provide for foreign withholding taxes on the current and future earnings of all of our foreign subsidiaries as the result of such reassessment.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTSIn December 2019, the Financial Accounting Standards Board issued ASU No. 2019-12, Income Taxes (Topic 740) (“ASU 2019-12”). ASU 2019-12 simplifies the accounting for income taxes by removing certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. ASU 2019-12 also adds guidance to reduce complexity in certain areas, including recognizing deferred taxes for tax goodwill and allocating taxes to members of a consolidated group. We adopted ASU 2019-12 on January 1, 2021. ASU 2019-12 did not have a material impact on our consolidated financial statements.
Segment Information	During the fourth quarter of 2020, we changed our definition of Adjusted EBITDA to (a) exclude stock-based compensation expense and (b) include our share of Adjusted EBITDA from our unconsolidated joint ventures. All prior periods have been recast to conform to these changes. We now define Adjusted EBITDA for each segment as net income (loss) before interest expense, net, provision (benefit) for income taxes, depreciation and amortization (inclusive of our share of Adjusted EBITDA from our unconsolidated joint ventures), and excluding certain items we do not believe to be indicative of our core operating results, specifically: EXCLUDED • Acquisition and Integration Costs • Other (income) expense, net • Restructuring Charges • Stock-based compensation expense • Intangible impairments • COVID-19 Costs (as defined below) • (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) Internally, we use Adjusted EBITDA as the basis for evaluating the performance of, and allocated resources to, our operating segments.
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIESWe are involved in litigation from time to time in the ordinary course of business, including litigation arising from damage to customer assets in our facilities caused by fires and other natural disasters. While the outcome of such litigation is inherently uncertain, we do not believe any current litigation will have a material adverse effect on our consolidated financial condition, results of operations or cash flows.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Schedule of allowance for credit loss	. The rollforward of the allowance for doubtful accounts and credit memo reserves for the nine months ended September 30, 2021 is as follows: Balance as of December 31, 2020 $ 56,981 Credit memos charged to revenue 29,996 Allowance for bad debts charged to expense 16,371 Deductions and other (1) (43,134) Balance as of September 30, 2021 $ 60,214 (1) Primarily consists of the issuance of credit memos, the write-off of accounts receivable, allowances associated with businesses acquired and the impact associated with currency translation adjustments.
Schedule of operating and financing lease right-of-use assets and lease liabilities	Operating and financing lease right-of-use assets and lease liabilities as of September 30, 2021 and December 31, 2020 are as follows: DESCRIPTION SEPTEMBER 30, 2021 DECEMBER 31, 2020 Assets: Operating lease right-of-use assets $ 2,308,047 $ 2,196,502 Financing lease right-of-use assets, net of accumulated depreciation (1) 307,032 310,534 Liabilities: Current Operating lease liabilities $ 257,884 $ 250,239 Financing lease liabilities (1) 42,442 43,149 Long-term Operating lease liabilities $ 2,164,449 $ 2,044,598 Financing lease liabilities (1) 321,682 323,162 (1) Financing lease right-of-use assets, current financing lease liabilities and long-term financing lease liabilities are included within Property, Plant and Equipment, Net, Current portion of long-term debt and Long-term Debt, net of current portion, respectively, within our Condensed Consolidated Balance Sheets.
Schedule of lease, cost	The components of the lease expense for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, DESCRIPTION 2021 2020 2021 2020 Operating lease cost (1) $ 140,551 $ 122,737 $ 408,312 $ 365,303 Financing lease cost: Depreciation of financing lease right-of-use assets $ 14,006 $ 12,973 $ 39,062 $ 38,495 Interest expense for financing lease liabilities 5,055 4,891 14,940 14,664 (1) Operating lease cost, the majority of which is included in Cost of sales, includes variable lease costs of $28,835 and $86,422 for the three and nine months ended September 30, 2021, respectively, and $27,486 and $82,287 for the three and nine months ended September 30, 2020, respectively. NINE MONTHS ENDED SEPTEMBER 30, CASH PAID FOR AMOUNTS INCLUDED IN MEASUREMENT OF LEASE LIABILITIES: 2021 2020 Operating cash flows used in operating leases $ 291,535 $ 266,619 Operating cash flows used in financing leases (interest) 14,940 14,664 Financing cash flows used in financing leases 35,360 36,008 NON-CASH ITEMS: Operating lease modifications and reassessments $ 103,158 $ 89,727 New operating leases (including acquisitions and sale-leaseback transactions) 240,822 173,635
Schedule of changes in the carrying value of goodwill attributable to each reportable operating segment	The changes in the carrying value of goodwill attributable to each reportable operating segment for the nine months ended September 30, 2021 are as follows: GLOBAL RIM BUSINESS GLOBAL DATA CENTER BUSINESS CORPORATE AND OTHER BUSINESS TOTAL CONSOLIDATED Goodwill balance, net of accumulated amortization as of December 31, 2020 $ 4,024,182 $ 436,987 $ 96,440 $ 4,557,609 Non-tax deductible goodwill acquired during the period 17,180 — 9,991 27,171 Goodwill allocated to IPM Divestment — — (46,105) (46,105) Fair value and other adjustments (6,091) — (1,268) (7,359) Currency effects (49,737) (7,995) (943) (58,675) Goodwill balance, net accumulated amortization as of September 30, 2021 $ 3,985,534 $ 428,992 $ 58,115 $ 4,472,641 Accumulated goodwill impairment balance as of September 30, 2021 $ 132,409 $ — $ 26,011 $ 158,420
Schedule of equity method investments	The carrying values and equity interests in our joint ventures at September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 CARRYING VALUE EQUITY INTEREST CARRYING VALUE EQUITY INTEREST Web Werks JV $ 51,257 38 % $ — — % Joint venture with AGC Equity Partners (the “Frankfurt JV”) 26,272 20 % 26,500 20 % Joint venture with MakeSpace Labs, Inc. (the “MakeSpace JV”) 27,419 48 % 16,924 39 %
Schedule of assets and liabilities carried at fair value measured on a recurring basis	The assets and liabilities carried at fair value measured on a recurring basis as of September 30, 2021 and December 31, 2020 are as follows: FAIR VALUE MEASUREMENTS AT SEPTEMBER 30, 2021 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 9,186 $ — $ 9,186 $ — Time Deposits 2,175 — 2,175 — Trading Securities 11,713 11,572 141 — Derivative Assets 1,214 — 1,214 — Derivative Liabilities 15,412 — 15,412 — FAIR VALUE MEASUREMENTS AT DECEMBER 31, 2020 USING DESCRIPTION TOTAL CARRYING QUOTED PRICES IN SIGNIFICANT OTHER SIGNIFICANT Money Market Funds $ 62,657 $ — $ 62,657 $ — Time Deposits 2,121 — 2,121 — Trading Securities 10,892 10,636 256 — Derivative Liabilities 49,703 — 49,703 —
Schedule of changes in accumulated other comprehensive items, net	The changes in accumulated other comprehensive items, net for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, 2021 NINE MONTHS ENDED SEPTEMBER 30, 2021 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (229,790) $ (28,863) $ (258,653) $ (206,190) $ (49,703) $ (255,893) Other comprehensive (loss) income): Foreign currency translation and other adjustments (90,465) — (90,465) (114,065) — (114,065) Change in fair value of derivative instruments — 14,665 14,665 — 35,505 35,505 Total other comprehensive (loss) income (90,465) 14,665 (75,800) (114,065) 35,505 (78,560) End of Period $ (320,255) $ (14,198) $ (334,453) $ (320,255) $ (14,198) $ (334,453) THREE MONTHS ENDED SEPTEMBER 30, 2020 NINE MONTHS ENDED SEPTEMBER 30, 2020 FOREIGN CHANGE IN FAIR VALUE OF TOTAL FOREIGN CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS TOTAL Beginning of Period $ (406,444) $ (21,079) $ (427,523) $ (252,825) $ (9,756) $ (262,581) Other comprehensive income (loss): Foreign currency translation and other adjustments 44,529 — 44,529 (109,090) — (109,090) Change in fair value of derivative instruments — (184) (184) — (11,507) (11,507) Total other comprehensive income (loss) 44,529 (184) 44,345 (109,090) (11,507) (120,597) End of Period $ (361,915) $ (21,263) $ (383,178) $ (361,915) $ (21,263) $ (383,178)
Schedule of cost and accumulated amortization associated with contract fulfillment costs	The costs associated with the initial movement of customer records into physical storage and certain commissions are considered costs to obtain or fulfill customer contracts (collectively, “Contract Fulfillment Costs”). Contract Fulfillment Costs as of September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 GROSS ACCUMULATED NET GROSS ACCUMULATED NET Intake Costs asset $ 71,540 $ (41,246) $ 30,294 $ 63,721 $ (33,352) $ 30,369 Commissions asset 107,298 (48,708) 58,590 91,069 (38,787) 52,282
Schedule of deferred revenue liabilities	Deferred revenue liabilities are reflected in our Condensed Consolidated Balance Sheets as follows: DESCRIPTION LOCATION IN BALANCE SHEET SEPTEMBER 30, 2021 DECEMBER 31, 2020 Deferred revenue - Current Deferred revenue $ 257,593 $ 295,785 Deferred revenue - Long-term Other Long-term Liabilities 34,342 35,612
Schedule of revenue	Our Global Data Center Business features storage rental provided to customers at contractually specified rates over a fixed contractual period, which are accounted for in accordance with Accounting Standards Update ("ASU") No. 2016-02, Leases (Topic 842) , as amended. Storage rental revenue, including revenue associated with power and connectivity, associated with our Global Data Center Business for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Storage rental revenue (1) $ 72,411 $ 68,416 $ 210,805 $ 196,823 (1) Revenue associated with power and connectivity included within storage rental revenue was $14,639 and $42,333 for the three and nine months ended September 30, 2021, respectively, and $12,033 and $34,986 for the three and nine months ended September 30, 2020, respectively.
Schedule of stock-based compensation expense	Stock-based compensation expense for the cost of stock options, restricted stock units (“RSUs”), performance units (“PUs”) and shares of stock issued under our employee stock purchase plan (collectively, “Employee Stock-Based Awards”) for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Stock-based compensation expense $ 13,200 $ 8,946 $ 46,852 $ 35,618
Schedule of vested and expected to vest	The fair value of RSUs and earned PUs that vested during the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Fair value of RSUs vested $ 8,425 $ 2,766 $ 31,404 $ 24,411 Fair value of earned PUs that vested 22,030 1,370 27,856 12,421
Schedule of components of gain/loss on sale/disposal of property, plant and equipment	THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 (1) 2021 (2) 2020 (1) (Gain) Loss on disposal/write-down of property, plant and equipment, net (3) $ (935) $ (75,840) $ (134,321) $ (78,170) (1) The gains for both the three and nine months ended September 30, 2020 primarily consisted of gains of approximately $76,400 associated with the sale-leaseback transactions of two facilities in the United States. (2) The gains for the nine months ended September 30, 2021 primarily consisted of gains of approximately $127,400 associated with the sale-leaseback transactions of five facilities in the United Kingdom, which occurred during the second quarter of 2021.
Schedule of other (income) expense, net	Consolidated other (income) expense, net for the three and nine months ended September 30, 2021 and 2020 consists of the following: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED DESCRIPTION 2021 2020 2021 2020 Foreign currency transaction (gains) losses, net $ (23,200) $ 29,635 $ (16,157) $ (6,293) Debt extinguishment expense — 51,260 — 68,300 Other, net (1) 4,699 2,570 (183,861) 4,432 Other (Income) Expense, Net $ (18,501) $ 83,465 $ (200,018) $ 66,439 (1) Other, net for the nine months ended September 30, 2021 is primarily comprised of (a) a gain of approximately $180,600 associated with our IPM Divestment and (b) a gain of approximately $20,300 associated with the loss of control and related deconsolidation, as of May 18, 2021, of one of our wholly owned Netherlands subsidiaries, for which we had value-added tax liability exposure that was recorded in 2019.
Schedule of income taxes	Our effective tax rates for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Effective Tax Rate (1) 29.1 % 26.5 % 28.1 % 25.7 %
Schedule of calculation of basic and diluted net income (loss) per share attributable to the entity	The calculation of basic and diluted income (loss) per share for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 68,111 $ 38,562 $ 391,264 $ 96,341 Less: Net Income (Loss) Attributable to Noncontrolling Interests 428 168 2,693 1,058 Net Income (Loss) Attributable to Iron Mountain Incorporated (utilized in numerator of Earnings Per Share calculation) $ 67,683 $ 38,394 $ 388,571 $ 95,283 Weighted-average shares—basic 289,762,000 288,403,000 289,255,000 288,105,000 Effect of dilutive potential stock options 869,600 14,758 522,642 28,723 Effect of dilutive potential RSUs and PUs 850,655 392,943 918,954 337,588 Weighted-average shares—diluted 291,482,255 288,810,701 290,696,596 288,471,311 Net Income (Loss) Per Share Attributable to Iron Mountain Incorporated: Basic $ 0.23 $ 0.13 $ 1.34 $ 0.33 Diluted $ 0.23 $ 0.13 $ 1.34 $ 0.33 Antidilutive stock options, RSUs and PUs, excluded from the calculation 351,673 5,529,126 1,813,880 5,959,693

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	PURCHASE PRICE ALLOCATION A summary of the cumulative consideration paid and the preliminary allocation of the purchase price paid for all of our 2021 acquisitions through September 30, 2021 is as follows: NINE MONTHS ENDED SEPTEMBER 30, 2021 Cash Paid (gross of cash acquired) $ 224,192 Fair Value of Noncontrolling Interests 3,878 Purchase Price Holdbacks and Other 2,534 Total Consideration 230,604 Fair Value of Identifiable Assets Acquired and Liabilities Assumed: Cash 20,440 Accounts Receivable, Prepaid Expenses and Other Assets 25,392 Property, Plant and Equipment (1) 147,132 Customer Relationship Intangible Assets (2) 39,315 Operating Lease Right-of-Use Assets 45,209 Data Center In-Place Leases (3) 4,994 Data Center Tenant Relationships (4) 4,682 Data Center Above-Market Leases (5) 1,042 Debt Assumed (9,026) Accounts Payable, Accrued Expenses and Other Liabilities (23,082) Operating Lease Liabilities (45,209) Deferred Income Taxes (7,436) Data Center Below-Market Leases (5) (20) Total Fair Value of Identifiable Net Assets Acquired 203,433 Goodwill Initially Recorded $ 27,171 (1) Consists primarily of land and building. (2) The preliminary weighted average lives of customer relationship intangible assets associated with acquisitions is 9 years. (3) The preliminary weighted average lives of data center in-place leases associated with acquisitions is 5 years. (4) The preliminary weighted average lives of data center tenant relationships associated with acquisitions is 5 years. (5) The preliminary weighted average lives of data center above-market leases associated with acquisitions is 5 years and the weighted average lives of data center below-market leases associated with acquisitions is 4 years.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	(Liabilities) assets recognized in our Condensed Consolidated Balance Sheets at September 30, 2021 and December 31, 2020, by derivative instrument, are as follows: DERIVATIVE INSTRUMENTS (1) SEPTEMBER 30, 2021 DECEMBER 31, 2020 Cash Flow Hedges (2) Interest Rate Swap Agreements $ (13,116) $ (21,062) Net Investment Hedges (3) August 2023 Cross-Currency Swap Agreements $ (2,296) $ (8,229) February 2026 Cross-Currency Swap Agreements 1,214 (20,412) (1) Our derivative assets are included as a component of Other assets in our Condensed Consolidated Balance Sheets and our derivative liabilities are included either as a component of (i) Accrued expenses and other current liabilities or (ii) Other long-term liabilities in our Condensed Consolidated Balance Sheets. As of September 30, 2021, $1,214 is included within Other assets, $4,296 is included within Accrued expenses and other current liabilities and $11,116 is included within Other long-term liabilities. As of December 31, 2020, $49,703 is included within Other long-term liabilities. (2) As of September 30, 2021, cumulative net losses of $13,116 are recorded within Accumulated other comprehensive items, net associated with these interest rate swap agreements. (3) As of September 30, 2021, cumulative net losses of $1,082 are recorded within Accumulated other comprehensive items, net associated with these cross-currency swap agreements.
Schedule of (Gains) Losses For Derivative Instruments	Unrealized gains (losses) recognized during the three and nine months ended September 30, 2021 and 2020, by derivative instrument, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, DERIVATIVE INSTRUMENTS (1) 2021 2020 2021 2020 Cash Flow Hedges Interest Rate Swap Agreements $ 1,950 $ 1,185 $ 7,946 $ (14,445) Net Investment Hedges August 2023 Cross-Currency Swap Agreements $ 2,655 $ (5,716) $ 5,933 $ (1,408) February 2026 Cross-Currency Swap Agreements 10,060 4,346 21,626 4,346
Schedule of Net Investment Hedges in AOCI	Foreign exchange gains (losses) associated with this hedge of net investment for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED 2021 (1) 2020 2021 (1) 2020 Foreign exchange gains (losses) associated with net investment hedge $ — $ (16,604) $ — $ (17,005) (1) As there are no hedges of net investment outstanding during the three and nine months ended September 30, 2021, no foreign exchange gains (losses) associated with hedges of net investment have been recognized.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Carrying Amount and Fair Value of Long-Term Debt Instruments	SEPTEMBER 30, 2021 DECEMBER 31, 2020 DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE DEBT (INCLUSIVE OF DISCOUNT) UNAMORTIZED DEFERRED FINANCING COSTS CARRYING AMOUNT FAIR VALUE Revolving Credit Facility (1) $ 310,000 $ (6,034) $ 303,966 $ 310,000 $ — $ (8,620) $ (8,620) $ — Term Loan A (1) 206,250 — 206,250 206,250 215,625 — 215,625 215,625 Term Loan B 674,540 (5,308) 669,232 675,500 679,621 (6,244) 673,377 680,750 Australian Dollar Term Loan (the “AUD Term Loan”) (2) 223,109 (881) 222,228 223,557 243,152 (1,624) 241,528 244,014 UK Bilateral Revolving Credit Facility (the “UK Bilateral Facility”) 188,431 (874) 187,557 188,431 191,101 (1,307) 189,794 191,101 3 7 / 8 % GBP Senior Notes due 2025 (the “GBP Notes”) 538,374 (4,151) 534,223 544,431 546,003 (4,983) 541,020 553,101 4 7 / 8 % Senior Notes due 2027 (the “4 7 / 8 % Notes due 2027”) (3) 1,000,000 (8,532) 991,468 1,035,000 1,000,000 (9,598) 990,402 1,046,250 5 1 / 4 % Senior Notes due 2028 (the “5 1 / 4 % Notes due 2028”) (3) 825,000 (7,676) 817,324 861,094 825,000 (8,561) 816,439 868,313 5% Senior Notes due 2028 (the “5% Notes”) (3) 500,000 (4,944) 495,056 521,250 500,000 (5,486) 494,514 523,125 4 7 / 8 % Senior Notes due 2029 (the “4 7 / 8 % Notes due 2029”) (3) 1,000,000 (11,573) 988,427 1,047,500 1,000,000 (12,658) 987,342 1,050,000 5 1 / 4 % Senior Notes due 2030 (the “5 1 / 4 Notes due 2030”) (3) 1,300,000 (13,287) 1,286,713 1,376,375 1,300,000 (14,416) 1,285,584 1,400,750 4 1 / 2 % Senior Notes due 2031 (the “4 1 / 2 % Notes”) (3) 1,100,000 (11,715) 1,088,285 1,111,000 1,100,000 (12,648) 1,087,352 1,138,500 5 5 / 8 % Senior Notes due 2032 (the “5 5 / 8 % Notes”) (3) 600,000 (6,292) 593,708 642,000 600,000 (6,727) 593,273 660,000 Real Estate Mortgages, Financing Lease Liabilities and Other 483,934 (905) 483,029 483,934 511,922 (1,086) 510,836 511,922 Accounts Receivable Securitization Program 266,400 (449) 265,951 266,400 85,000 (152) 84,848 85,000 Total Long-term Debt 9,216,038 (82,621) 9,133,417 8,797,424 (94,110) 8,703,314 Less Current Portion (319,025) 881 (318,144) (193,759) — (193,759) Long-term Debt, Net of Current Portion $ 8,897,013 $ (81,740) $ 8,815,273 $ 8,603,665 $ (94,110) $ 8,509,555 (1) Collectively, the “Credit Agreement”. The Credit Agreement consists of a revolving credit facility (the “Revolving Credit Facility”) and a term loan (the “Term Loan A”). The Credit Agreement is scheduled to mature on June 3, 2023. In addition, we also had various outstanding letters of credit totaling $3,064. The remaining amount available for borrowing under the Revolving Credit Facility as of September 30, 2021 was $1,436,936 (which amount represents the maximum availability as of such date). The average interest rate in effect under the Credit Agreement was 1.8% and 1.9% as of September 30, 2021 and December 31, 2020, respectively. (2) The AUD Term Loan is scheduled to mature on September 22, 2022, at which point all obligations become due. The full amount of the AUD Term Loan is classified within the current portion of long-term debt in our Condensed Consolidated Balance Sheet as of September 30, 2021. (3) Collectively, the “Parent Notes”.
Schedule of Net Cash Position in Cash Pool Agreements	The approximate amount of the net cash position for our cash pools and the approximate amount of the gross position and outstanding debit balances for each of these pools as of September 30, 2021 and December 31, 2020 are as follows: SEPTEMBER 30, 2021 DECEMBER 31, 2020 GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION GROSS CASH POSITION OUTSTANDING DEBIT BALANCES NET CASH POSITION BMG QRS Cash Pool $ 566,100 $ (562,400) $ 3,700 $ 448,700 $ (447,400) $ 1,300 BMG TRS Cash Pool 579,300 (578,300) 1,000 555,500 (553,500) 2,000 JPM QRS Cash Pool 4,200 (2,300) 1,900 — — — JPM TRS Cash Pool 5,200 (4,700) 500 — — —

Stockholders' Equity Matters (T

Stockholders' Equity Matters (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Schedule of dividend declared and payments	In fiscal year 2020 and the nine months ended September 30, 2021, our board of directors declared the following dividends: DECLARATION DATE DIVIDEND RECORD DATE TOTAL PAYMENT DATE February 13, 2020 $ 0.6185 March 16, 2020 $ 178,047 April 6, 2020 May 5, 2020 0.6185 June 15, 2020 178,212 July 2, 2020 August 5, 2020 0.6185 September 15, 2020 178,224 October 2, 2020 November 4, 2020 0.6185 December 15, 2020 178,290 January 6, 2021 February 24, 2021 0.6185 March 15, 2021 178,569 April 6, 2021 May 6, 2021 0.6185 June 15, 2021 179,026 July 6, 2021 August 5, 2021 0.6185 September 15, 2021 179,080 October 6, 2021

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Schedule of analysis of business segment information	An analysis of our business segment information and reconciliation to the accompanying Condensed Consolidated Financial Statements for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED NINE MONTHS ENDED 2021 2020 2021 2020 Global RIM Business Total Revenues $ 995,577 $ 921,773 $ 2,955,803 $ 2,755,294 Adjusted EBITDA 442,798 393,883 1,281,668 1,169,671 Global Data Center Business Total Revenues $ 88,587 $ 72,814 $ 236,672 $ 206,939 Adjusted EBITDA 35,097 33,359 98,961 94,812 Corporate and Other Business Total Revenues $ 45,984 $ 42,060 $ 139,469 $ 125,384 Adjusted EBITDA (60,126) (51,230) (176,664) (163,010) Total Consolidated Total Revenues $ 1,130,148 $ 1,036,647 $ 3,331,944 $ 3,087,617 Adjusted EBITDA 417,769 376,012 1,203,965 1,101,473
Schedule of reconciliation of net income (loss) to Adjusted EBITDA	A reconciliation of Net Income (Loss) to Adjusted EBITDA on a consolidated basis for the three and nine months ended September 30, 2021 and 2020 is as follows: THREE MONTHS ENDED NINE MONTHS ENDED 2021 2020 2021 2020 Net Income (Loss) $ 68,111 $ 38,562 $ 391,264 $ 96,341 Add/(Deduct): Interest expense, net 103,809 104,303 313,451 313,408 Provision (benefit) for income taxes 28,017 13,934 153,073 33,304 Depreciation and amortization 174,818 157,252 507,145 483,686 Acquisition and Integration Costs 1,138 — 3,415 — Restructuring Charges 50,432 48,371 129,686 128,715 Intangible impairments — — — 23,000 (Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate) (935) (75,840) (134,321) (78,170) Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures (21,517) 81,190 (209,001) 59,398 Stock-based compensation expense (1) 12,644 8,065 45,913 32,056 COVID-19 Costs (2) — — — 9,285 Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures 1,252 175 3,340 450 Adjusted EBITDA $ 417,769 $ 376,012 $ 1,203,965 $ 1,101,473 (1) Stock-based compensation expense related to Project Summit is included within Restructuring Charges for the three and nine months ended September 30, 2021 and 2020. (2) Costs that are incremental and directly attributable to the COVID-19 pandemic which are not expected to recur once the pandemic ends ("COVID-19 Costs"). These costs include the purchase of personal protective equipment for our employees and incremental cleaning costs of our facilities, among other direct costs.
Schedule of revenues by product and service lines by segment	Information as to our revenues by product and service lines by segment for the three and nine months ended September 30, 2021 and 2020 are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, 2021 2020 2021 2020 Global RIM Business Records Management (1) $ 767,059 $ 712,182 $ 2,285,000 $ 2,118,767 Data Management (1) 115,261 121,936 351,914 367,093 Information Destruction (1)(2) 113,257 87,655 318,889 269,434 Data Center (1) — — — — Global Data Center Business Records Management (1) $ — $ — $ — $ — Data Management (1) — — — — Information Destruction (1)(2) — — — — Data Center (1) 88,587 72,814 236,672 206,939 Corporate and Other Business Records Management (1) $ 30,453 $ 25,720 $ 91,461 $ 75,675 Data Management (1) 15,531 16,340 48,008 49,709 Information Destruction (1)(2) — — — — Data Center (1) — — — — Total Consolidated Records Management (1) $ 797,512 $ 737,902 $ 2,376,461 $ 2,194,442 Data Management (1) 130,792 138,276 399,922 416,802 Information Destruction (1)(2) 113,257 87,655 318,889 269,434 Data Center (1) 88,587 72,814 236,672 206,939 (1) Each of the offerings within our product and service lines has a component of revenue that is storage rental related and a component that is service revenues, except for information destruction, which does not have a storage rental component. (2) Includes secure shredding services.

Project Summit (Tables)

Project Summit (Tables)	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
Schedule of restructuring charges and restructuring liability rollforward	Restructuring Charges included in the accompanying Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2021 and 2020, and from the inception of Project Summit through September 30, 2021, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, FROM THE INCEPTION 2021 2020 2021 2020 Employee severance costs $ 6,797 $ 13,579 $ 14,526 $ 31,229 $ 82,725 Professional fees and other costs 43,635 34,792 115,160 97,486 289,954 Restructuring Charges $ 50,432 $ 48,371 $ 129,686 $ 128,715 $ 372,679 Restructuring Charges by segment for the three and nine months ended September 30, 2021 and 2020, and from the inception of Project Summit through September 30, 2021, are as follows: THREE MONTHS ENDED SEPTEMBER 30, NINE MONTHS ENDED SEPTEMBER 30, FROM THE INCEPTION 2021 2020 2021 2020 Global RIM Business $ 11,362 $ 16,183 $ 27,528 $ 37,245 $ 116,568 Global Data Center Business 1,285 296 2,922 986 4,860 Corporate and Other Business 37,785 31,892 99,236 90,484 251,251 Restructuring Charges $ 50,432 $ 48,371 $ 129,686 $ 128,715 $ 372,679 A rollforward of the accrued Restructuring Charges, which is included as a component of Accrued expenses and other current liabilities in our Condensed Consolidated Balance Sheets, from December 31, 2019 through September 30, 2021, is as follows: EMPLOYEE SEVERANCE COSTS PROFESSIONAL FEES AND OTHER TOTAL ACCRUED RESTRUCTURING CHARGES Balance as of December 31, 2019 $ 4,823 $ 12,954 $ 17,777 Amounts accrued 47,349 147,047 194,396 Payments (32,455) (136,222) (168,677) Other, including currency translation adjustments (3,439) (4) (3,443) Balance as of December 31, 2020 16,278 23,775 40,053 Amounts accrued 14,525 115,161 129,686 Payments (20,771) (112,714) (133,485) Other, including currency translation adjustments (939) — (939) Balance as of September 30, 2021 $ 9,093 $ 26,222 $ 35,315

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Allowance for Doubtful Accounts and Credit Memo Reserves (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance as of December 31, 2020	$ 56,981
Credit memos charged to revenue	29,996
Allowance for bad debts charged to expense	16,371
Deductions and other	(43,134)
Balance as of September 30, 2021	$ 60,214

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Supplemental Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Operating lease right-of-use assets	$ 2,308,047	$ 2,196,502
Financing lease right-of-use assets, net of accumulated depreciation	307,032	310,534
Current
Operating lease liabilities	257,884	250,239
Finance lease liabilities	42,442	43,149
Long-term
Operating lease liabilities	2,164,449	2,044,598
Finance lease liabilities	$ 321,682	$ 323,162
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)	Accrued expenses and other current liabilities (includes current portion of operating lease liabilities)
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Current portion of long-term debt	Current portion of long-term debt
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term Debt, net of current portion	Long-term Debt, net of current portion

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Leases Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Operating lease cost	$ 140,551	$ 122,737	$ 408,312	$ 365,303
Depreciation of financing lease right-of-use assets	14,006	12,973	39,062	38,495
Interest expense for financing lease liabilities	5,055	4,891	14,940	14,664
Variable lease costs	$ 28,835	$ 27,486	$ 86,422	$ 82,287

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Supplemental Cash Flows (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Operating cash flows used in operating leases	$ 291,535	$ 266,619
Operating cash flows used in financing leases (interest)	14,940	14,664
Financing cash flows used in financing leases	35,360	36,008
Operating lease modifications and reassessments	103,158	89,727
New operating leases (including acquisitions and sale-leaseback transactions)	$ 240,822	$ 173,635

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Schedule of Changes in Carrying Value of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	$ 4,557,609
Non-tax deductible goodwill acquired during the period	27,171
Goodwill allocated to IPM Divestment	(46,105)
Fair value and other adjustments	(7,359)
Currency effects	(58,675)
Goodwill ending balance	4,472,641
Accumulated goodwill impairment	158,420
GLOBAL RIM BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	4,024,182
Non-tax deductible goodwill acquired during the period	17,180
Goodwill allocated to IPM Divestment	0
Fair value and other adjustments	(6,091)
Currency effects	(49,737)
Goodwill ending balance	3,985,534
Accumulated goodwill impairment	132,409
GLOBAL DATA CENTER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	436,987
Non-tax deductible goodwill acquired during the period	0
Goodwill allocated to IPM Divestment	0
Fair value and other adjustments	0
Currency effects	(7,995)
Goodwill ending balance	428,992
Accumulated goodwill impairment	0
CORPORATE AND OTHER BUSINESS
Gross amount of goodwill [Roll Forward]
Goodwill beginning balance	96,440
Non-tax deductible goodwill acquired during the period	9,991
Goodwill allocated to IPM Divestment	(46,105)
Fair value and other adjustments	(1,268)
Currency effects	(943)
Goodwill ending balance	58,115
Accumulated goodwill impairment	$ 26,011

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Investments Narrative (Details) ₨ in Thousands, $ in Thousands	Sep. 30, 2021USD ($)	Apr. 30, 2021INR (₨)	Apr. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Web Werks JV
Schedule of Equity Method Investments [Line Items]
Equity method investments, fair value disclosure		₨ 3,750,000	$ 50,100
Additional equity method investments, fair value disclosure		₨ 7,500,000	$ 100,000
Equity investments	$ 51,257			$ 0
Ownership percentage	38.00%			0.00%
Frankfurt JV
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 26,272			$ 26,500
Ownership percentage	20.00%			20.00%
MakeSpace JV
Schedule of Equity Method Investments [Line Items]
Equity investments	$ 27,419			$ 16,924
Ownership percentage	48.00%			39.00%

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Fair Value Measurements (Details) - Fair value measured on recurring basis - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	$ 11,572	$ 10,636
Derivative asset	0
Derivative liability	0	0
SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	141	256
Derivative asset	1,214
Derivative liability	15,412	49,703
SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	0	0
Derivative asset	0
Derivative liability	0	0
Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Trading securities	11,713	10,892
Derivative asset	1,214
Derivative liability	15,412	49,703
Money Market Funds | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Money Market Funds | SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	9,186	62,657
Money Market Funds | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Money Market Funds | Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	9,186	62,657
Bank Time Deposits | QUOTED PRICES IN ACTIVE MARKETS (LEVEL 1)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Bank Time Deposits | SIGNIFICANT OTHER OBSERVABLE INPUTS (LEVEL 2)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	2,175	2,121
Bank Time Deposits | SIGNIFICANT UNOBSERVABLE INPUTS (LEVEL 3)
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	0	0
Bank Time Deposits | Estimate of Fair Value Measurement
Assets and Liabilities Carried at Fair Value Measured on a Recurring Basis [Line Items]
Money market funds	$ 2,175	$ 2,121

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income and Other Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Rollforward
Beginning of Period	$ 1,147,742	$ 1,024,331	$ 1,136,729	$ 1,464,227
Other comprehensive (loss) income):
Foreign currency translation and other adjustments	(90,465)	44,529	(114,065)	(109,090)
Change in fair value of derivative instruments	14,665	(184)	35,505	(11,507)
Total other comprehensive (loss) income	(75,800)	44,345	(78,560)	(120,597)
End of period	975,146	937,246	975,146	937,246
FOREIGN CURRENCY TRANSLATION AND OTHER ADJUSTMENTS
AOCI Rollforward
Beginning of Period	(229,790)	(406,444)	(206,190)	(252,825)
Other comprehensive (loss) income):
Foreign currency translation and other adjustments	(90,465)	44,529	(114,065)	(109,090)
Change in fair value of derivative instruments	0	0	0	0
Total other comprehensive (loss) income	(90,465)	44,529	(114,065)	(109,090)
End of period	(320,255)	(361,915)	(320,255)	(361,915)
CHANGE IN FAIR VALUE OF DERIVATIVE INSTRUMENTS
AOCI Rollforward
Beginning of Period	(28,863)	(21,079)	(49,703)	(9,756)
Other comprehensive (loss) income):
Foreign currency translation and other adjustments	0	0	0	0
Change in fair value of derivative instruments	14,665	(184)	35,505	(11,507)
Total other comprehensive (loss) income	14,665	(184)	35,505	(11,507)
End of period	(14,198)	(21,263)	(14,198)	(21,263)
TOTAL
AOCI Rollforward
Beginning of Period	(258,653)	(427,523)	(255,893)	(262,581)
Other comprehensive (loss) income):
End of period	$ (334,453)	$ (383,178)	$ (334,453)	$ (383,178)

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Contract Fulfillment Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Intake Costs
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	$ 71,540	$ 63,721
ACCUMULATED AMORTIZATION	(41,246)	(33,352)
NET CARRYING AMOUNT	30,294	30,369
Commissions
Contract With Customer, Asset And Liabilities [Line Items]
GROSS CARRYING AMOUNT	107,298	91,069
ACCUMULATED AMORTIZATION	(48,708)	(38,787)
NET CARRYING AMOUNT	$ 58,590	$ 52,282

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Summary of Deferred Revenue Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Deferred revenue - Current	$ 257,593	$ 295,785
Deferred revenue - Long-term	$ 34,342	$ 35,612

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Storage Rental (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lessor, Lease, Description [Line Items]
Storage rental	$ 718,614	$ 696,294	$ 2,144,942	$ 2,056,797
GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	72,411	68,416	210,805	196,823
Storage Rental, Power and Connectivity | GLOBAL DATA CENTER BUSINESS
Lessor, Lease, Description [Line Items]
Storage rental	$ 14,639	$ 12,033	$ 42,333	$ 34,986

Summary of Significant Accou_15

Summary of Significant Accounting Policies - Stock-Based Compensation Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 48,494		$ 48,494
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 13,200	$ 8,946	$ 46,852	$ 35,618
Two Thousand Twenty One
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets	133.00%		133.00%
Two Thousand Twenty
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets		114.00%		114.00%
Two Thousand Nineteen
Performance Units Disclosure
Percentage of achievement of the predefined revenue and ROIC targets						103.00%
2014 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of our common stock authorized for issuance (in shares)			8,000,000
Shares of our common stock authorized for issuance (in shares)	20,750,000		20,750,000		12,750,000
2013 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of our common stock authorized for issuance (in shares)			1,000,000
Shares of our common stock authorized for issuance (in shares)	2,000,000		2,000,000		1,000,000
Restricted Stock Units
Summary of Option Activity
Total fair value of shares or units vested	$ 8,425	$ 2,766	$ 31,404	$ 24,411
Performance units
Summary of Option Activity
Total fair value of shares or units vested	$ 22,030	$ 1,370	$ 27,856	$ 12,421

Summary of Significant Accou_16

Summary of Significant Accounting Policies - Acquisition and Integration costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Acquisition and Integration Costs	$ 1,138	$ 0	$ 3,415	$ 0

Summary of Significant Accou_17

Summary of Significant Accounting Policies - (Gain) Loss on Disposal/Write-Down of Property, Plant and Equipment, Net (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Gain) loss on disposal/write-down of property, plant and equipment, net	$ (935,000)	$ (75,840,000)	$ (134,321,000)	$ (78,170,000)
Facilities In The United Kingdom
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sale and sale-leaseback transactions		$ 76,400,000	$ 127,400,000	$ 76,400,000
Number Of Sale Lease back Properties			5	2

Summary of Significant Accou_18

Summary of Significant Accounting Policies - Other (Income) Expense, Net (Details) - USD ($) $ in Thousands	May 18, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Foreign currency transaction (gains) losses, net		$ (23,200)	$ 29,635	$ (16,157)	$ (6,293)
Debt extinguishment expense		0	51,260	0	68,300
Other, net		4,699	2,570	(183,861)	4,432
Other (Income) Expense, Net		$ (18,501)	$ 83,465	(200,018)	66,439
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on divestment	$ 20,300			180,569	$ 0
IPM Divestment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on divestment				$ 180,600

Summary of Significant Accou_19

Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounting Policies [Abstract]
Effective Tax Rate(1)	29.10%	26.50%	28.10%	25.70%
Expense related to change in enacted tax law			$ 12,000

Summary of Significant Accou_20

Summary of Significant Accounting Policies - Income (Loss) Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income (Loss) Per Share-Basic and Diluted
Net Income (Loss)	$ 68,111	$ 38,562	$ 391,264	$ 96,341
Less: Net Income (Loss) Attributable to Noncontrolling Interests	428	168	2,693	1,058
Net Income (Loss) Attributable to Iron Mountain Incorporated	$ 67,683	$ 38,394	$ 388,571	$ 95,283
Weighted-average shares—basic (in shares)	289,762,000	288,403,000	289,255,000	288,105,000
Effect of dilutive potential stock options (in shares)	869,600	14,758	522,642	28,723
Effect of dilutive potential restricted stock, RSUs and PUs (in shares)	850,655	392,943	918,954	337,588
Weighted-average shares—diluted (in shares)	291,482,255	288,810,701	290,696,596	288,471,311
Income (Loss) from Continuing Operations, Basic (in dollars per share)	$ 0.23	$ 0.13	$ 1.34	$ 0.33
Income (Loss) from Continuing Operations, Diluted (in dollars per share)	$ 0.23	$ 0.13	$ 1.34	$ 0.33
Antidilutive stock options, RSUs and PUs, excluded from the calculation (in shares)	351,673	5,529,126	1,813,880	5,959,693

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) € in Thousands	Sep. 23, 2021USD ($)	Sep. 23, 2021EUR (€)	Sep. 15, 2021USD ($)	Sep. 30, 2021USD ($)
InfoFort
Business Acquisition [Line Items]
Cash consideration			$ 90,300,000
Frankfurt Data Center
Business Acquisition [Line Items]
Cash consideration	$ 91,300,000	€ 77,900
Records Management Company
Business Acquisition [Line Items]
Number of businesses acquired				2
Art Storage Company
Business Acquisition [Line Items]
Number of businesses acquired				1
Records Management Companies And Art Storage Company
Business Acquisition [Line Items]
Cash consideration				$ 45,100,000

Acquisitions - Schedule of Purc

Acquisitions - Schedule of Purchase Price Allocation (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Operating Lease Liabilities	$ (2,164,449)	$ (2,044,598)
Data Center Below-Market Leases	(20)
Goodwill Initially Recorded	$ 4,472,641	$ 4,557,609
Customer Relationships
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life	9 years
Leases, Acquired-in-Place
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life	5 years
Tenant Relationships
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life	5 years
Above Market Leases
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life	5 years
Below Market Leases
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Acquired finite-lived intangible assets, weighted average useful life	4 years
2021 Acquisitions
Business Acquisition [Line Items]
Cash Paid (gross of cash acquired)	$ 224,192
Fair Value of Noncontrolling Interests	3,878
Purchase Price Holdbacks and Other	2,534
Total Consideration	230,604
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Cash	20,440
Accounts Receivable, Prepaid Expenses and Other Assets	25,392
Property, Plant and Equipment	147,132
Operating Lease Right-of-Use Assets	45,209
Debt Assumed	(9,026)
Accounts Payable, Accrued Expenses and Other Liabilities	(23,082)
Operating Lease Liabilities	(45,209)
Deferred Income Taxes	(7,436)
Total Fair Value of Identifiable Net Assets Acquired	203,433
Goodwill Initially Recorded	27,171
2021 Acquisitions | Customer Relationships
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Intangible Assets	39,315
2021 Acquisitions | Leases, Acquired-in-Place
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Intangible Assets	4,994
2021 Acquisitions | Tenant Relationships
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Intangible Assets	4,682
2021 Acquisitions | Above Market Leases
Fair Value of Identifiable Assets Acquired and Liabilities Assumed:
Intangible Assets	$ 1,042

Divestments (Details)

Divestments (Details) - USD ($) $ in Thousands	May 18, 2021	Sep. 30, 2021	Sep. 30, 2020	Jun. 07, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on IPM Divestment	$ 20,300	$ 180,569	$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Iron Mountain Intellectual Property Divestiture
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total gross consideration				$ 216,600
Gain on IPM Divestment		$ 180,600

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Additional Information (Details)	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020EUR (€)	Aug. 31, 2020	Mar. 31, 2020EUR (€)	Aug. 31, 2019USD ($)	Aug. 31, 2019EUR (€)	Jul. 31, 2019USD ($)
Euro Notes
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Stated interest rate (as a percent)					3.00%
Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net gains	$ (1,082,000)
Net Investment Hedges | Designated as Hedging Instrument | Euro Notes
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Hedged notes | €						€ 300,000,000
Cumulative net gains	3,256,000
Interest Rate Swap Agreements
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount	$ 350,000,000	$ 350,000,000							$ 350,000,000
Cross-currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Notional amount			$ 359,200,000	€ 300,000,000			$ 110,000,000	€ 99,055,000
Interest rate			4.50%	4.50%			6.00%	6.00%
Weighted average interest rate			3.40%	3.40%			3.65%	3.65%

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Net Investment Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Other Assets, Net
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative asset	$ 1,214		$ 1,214
Accrued Expenses And Other Current Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(4,296)		(4,296)
Other Long-Term Liabilities
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(11,116)		(11,116)		$ (49,703)
Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in cross-currency swaps	1,082		1,082
Interest Rate Swap Agreements
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative net losses in AOCI	13,116		13,116
Interest Rate Swap Agreements | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(13,116)		(13,116)		(21,062)
Interest Rate Swap Agreements | Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with interest rate swap agreements	1,950	$ 1,185	7,946	$ (14,445)
August 2023 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative liabilities	(2,296)		(2,296)		(8,229)
August 2023 Cross Currency Swap Agreements | Designated as Hedging Instrument | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with cross-currency swaps	2,655	(5,716)	5,933	(1,408)
February 2026 Cross Currency Swap Agreements | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Derivative asset	1,214		1,214
Derivative liabilities					$ (20,412)
February 2026 Cross Currency Swap Agreements | Designated as Hedging Instrument | Net Investment Hedges
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Unrealized gains (losses) associated with cross-currency swaps	$ 10,060	$ 4,346	$ 21,626	$ 4,346

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Hedge of Net Investment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign exchange gains (losses) associated with net investment hedge	$ 0	$ (16,604)	$ 0	$ (17,005)

Debt - Schedule of Long Term De

Debt - Schedule of Long Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	$ 9,216,038	$ 8,797,424
UNAMORTIZED DEFERRED FINANCING COSTS	(82,621)	(94,110)
CARRYING AMOUNT	9,133,417	8,703,314
Long-term debt, gross, current maturities	(319,025)	(193,759)
Long term debt, gross, net of current portion	8,897,013	8,603,665
Unamortized debt issuance expense, net of current portion	881	0
Unamortized debt issuance expense, net	(81,740)	(94,110)
Carrying amount, current maturities	(318,144)	(193,759)
Carrying amount, excluding current maturities	8,815,273	8,509,555
Australian Dollar Term Loan (the AUD Term Loan)
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	223,109	243,152
UNAMORTIZED DEFERRED FINANCING COSTS	(881)	(1,624)
CARRYING AMOUNT	222,228	241,528
FAIR VALUE	223,557	244,014
Real Estate Mortgages, Financing Lease Liabilities and Other
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	483,934	511,922
UNAMORTIZED DEFERRED FINANCING COSTS	(905)	(1,086)
CARRYING AMOUNT	483,029	510,836
FAIR VALUE	483,934	511,922
Accounts Receivable Securitization Program
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	266,400	85,000
UNAMORTIZED DEFERRED FINANCING COSTS	(449)	(152)
CARRYING AMOUNT	265,951	84,848
FAIR VALUE	266,400	$ 85,000
Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	36,506
Revolving Credit Facility | Credit Agreement
Debt Instrument [Line Items]
Letters of credit outstanding	3,064
Remaining capacity	$ 1,436,936
Weighted average interest rate	1.80%	1.90%
New Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	$ 310,000	$ 0
UNAMORTIZED DEFERRED FINANCING COSTS	(6,034)	(8,620)
CARRYING AMOUNT	303,966	(8,620)
FAIR VALUE	310,000	0
Term Loan A | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	206,250	215,625
UNAMORTIZED DEFERRED FINANCING COSTS	0	0
CARRYING AMOUNT	206,250	215,625
FAIR VALUE	206,250	215,625
Term Loan B | Term Loan Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	674,540	679,621
UNAMORTIZED DEFERRED FINANCING COSTS	(5,308)	(6,244)
CARRYING AMOUNT	669,232	673,377
FAIR VALUE	675,500	680,750
UK Bilateral Revolving Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
DEBT (INCLUSIVE OF DISCOUNT)	188,431	191,101
UNAMORTIZED DEFERRED FINANCING COSTS	(874)	(1,307)
CARRYING AMOUNT	187,557	189,794
FAIR VALUE	$ 188,431	191,101
GBP Senior Notes due 2025 3.875 Percent | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	3.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 538,374	546,003
UNAMORTIZED DEFERRED FINANCING COSTS	(4,151)	(4,983)
CARRYING AMOUNT	534,223	541,020
FAIR VALUE	$ 544,431	553,101
Senior Notes 4.875 Percent due 2027 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,000,000	1,000,000
UNAMORTIZED DEFERRED FINANCING COSTS	(8,532)	(9,598)
CARRYING AMOUNT	991,468	990,402
FAIR VALUE	$ 1,035,000	1,046,250
Senior Notes 5.25 Percent due 2028 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.25%
DEBT (INCLUSIVE OF DISCOUNT)	$ 825,000	825,000
UNAMORTIZED DEFERRED FINANCING COSTS	(7,676)	(8,561)
CARRYING AMOUNT	817,324	816,439
FAIR VALUE	$ 861,094	868,313
Senior Notes 5 Percent Due 2028 Member | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.00%
DEBT (INCLUSIVE OF DISCOUNT)	$ 500,000	500,000
UNAMORTIZED DEFERRED FINANCING COSTS	(4,944)	(5,486)
CARRYING AMOUNT	495,056	494,514
FAIR VALUE	$ 521,250	523,125
Senior Notes 4.875 Percent due 2029 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.875%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,000,000	1,000,000
UNAMORTIZED DEFERRED FINANCING COSTS	(11,573)	(12,658)
CARRYING AMOUNT	988,427	987,342
FAIR VALUE	$ 1,047,500	1,050,000
Senior Notes 5.25 Percent Due 2030 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.25%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,300,000	1,300,000
UNAMORTIZED DEFERRED FINANCING COSTS	(13,287)	(14,416)
CARRYING AMOUNT	1,286,713	1,285,584
FAIR VALUE	$ 1,376,375	1,400,750
Senior Notes 4.5 Percent Due 2031 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	4.50%
DEBT (INCLUSIVE OF DISCOUNT)	$ 1,100,000	1,100,000
UNAMORTIZED DEFERRED FINANCING COSTS	(11,715)	(12,648)
CARRYING AMOUNT	1,088,285	1,087,352
FAIR VALUE	$ 1,111,000	1,138,500
Senior Notes 5.625 Percent Due 2032 | Senior Notes
Debt Instrument [Line Items]
Stated interest rate (as a percent)	5.625%
DEBT (INCLUSIVE OF DISCOUNT)	$ 600,000	600,000
UNAMORTIZED DEFERRED FINANCING COSTS	(6,292)	(6,727)
CARRYING AMOUNT	593,708	593,273
FAIR VALUE	$ 642,000	$ 660,000

Debt - UK Bilateral Revolving C

Debt - UK Bilateral Revolving Credit Facility (Details) - Revolving Credit Facility - UK Bilateral Revolving Credit Facility £ in Thousands	May 25, 2021extension	May 24, 2021	Sep. 30, 2021GBP (£)
Debt Instrument [Line Items]
Number of extensions | extension	2
Period of extension	1 year
Maximum borrowing capacity			£ 140,000
Additional borrowing capacity			£ 125,000
Interest rate at period end			2.10%
London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%	2.25%

Debt - Accounts Receivable Secu

Debt - Accounts Receivable Securitization Program (Details) - USD ($) $ in Thousands	Jun. 28, 2021	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Outstanding borrowings		$ 9,133,417	$ 8,703,314
Effective interest rate (as a percent)		1.10%
Accounts Receivable Securitization Program
Debt Instrument [Line Items]
Outstanding borrowings		$ 266,400
Accounts Receivable Securitization Program | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%

Debt - Cash Pooling (Details)

Debt - Cash Pooling (Details) $ in Thousands	3 Months Ended
	Sep. 30, 2021USD ($)cash_pool	Dec. 31, 2020USD ($)
JP Morgan Chase Bank
Debt Instrument [Line Items]
Number of cash pools | cash_pool	2
Bank Mendes Gans
Debt Instrument [Line Items]
Number of cash pools | cash_pool	2
QRS Cash Pool | JP Morgan Chase Bank
Debt Instrument [Line Items]
Cash pool borrowings	$ 12,000
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 4,200	$ 0
OUTSTANDING DEBIT BALANCES	(2,300)	0
NET CASH POSITION	$ 1,900	0
QRS Cash Pool | Bank Mendes Gans
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 566,100	448,700
OUTSTANDING DEBIT BALANCES	(562,400)	(447,400)
NET CASH POSITION	3,700	1,300
TRS Cash Pool | JP Morgan Chase Bank
Debt Instrument [Line Items]
Cash pool borrowings	$ 10,000
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 5,200	0
OUTSTANDING DEBIT BALANCES	(4,700)	0
NET CASH POSITION	$ 500	0
TRS Cash Pool | Bank Mendes Gans
Debt Instrument [Line Items]
Number of cash pools | cash_pool	1
GROSS CASH POSITION	$ 579,300	555,500
OUTSTANDING DEBIT BALANCES	(578,300)	(553,500)
NET CASH POSITION	$ 1,000	$ 2,000

Debt - Letters of Credit (Detai

Debt - Letters of Credit (Details) - Credit Agreement $ in Thousands	Sep. 30, 2021USD ($)
Debt Instrument [Line Items]
Letters of credit outstanding	$ 36,506
Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding	$ 3,064

Commitments and Contingencies -

Commitments and Contingencies - (Details) $ in Thousands	Sep. 30, 2021USD ($)
Insurance settlement
Commitments and Contingencies
Reasonably possible additional losses	$ 26,000

Stockholders' Equity Matters -

Stockholders' Equity Matters - Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Thousands	Nov. 04, 2021	Sep. 15, 2021	Aug. 05, 2021	Jun. 15, 2021	May 06, 2021	Mar. 15, 2021	Feb. 24, 2021	Dec. 15, 2020	Nov. 04, 2020	Sep. 15, 2020	Aug. 05, 2020	Jun. 15, 2020	May 05, 2020	Mar. 16, 2020	Feb. 13, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Dividends Payable [Line Items]
DIVIDEND PER SHARE (in dollars per share)			$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185		$ 0.6185
TOTAL AMOUNT		$ 179,080		$ 179,026		$ 178,569		$ 178,290		$ 178,224		$ 178,212		$ 178,047		$ 180,600	$ 179,677	$ 540,045	$ 538,531
Subsequent Event
Dividends Payable [Line Items]
DIVIDEND PER SHARE (in dollars per share)	$ 0.6185

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020segment
Segment Reporting [Abstract]
Number of operating segments	3

Segment Information - Segment R

Segment Information - Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,130,148	$ 1,036,647	$ 3,331,944	$ 3,087,617
Adjusted EBITDA	417,769	376,012	1,203,965	1,101,473
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	995,577	921,773	2,955,803	2,755,294
Adjusted EBITDA	442,798	393,883	1,281,668	1,169,671
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	88,587	72,814	236,672	206,939
Adjusted EBITDA	35,097	33,359	98,961	94,812
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	45,984	42,060	139,469	125,384
Adjusted EBITDA	$ (60,126)	$ (51,230)	$ (176,664)	$ (163,010)

Segment Information - Reconcili

Segment Information - Reconciliation to of Net Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		24 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021
Reconciliation to of Net Income to Adjusted EBITDA
Net Income (Loss)	$ 68,111	$ 38,562	$ 391,264	$ 96,341
Interest expense, net	103,809	104,303	313,451	313,408
Provision (benefit) for income taxes	28,017	13,934	153,073	33,304
Depreciation and amortization	174,818	157,252	507,145	483,686
Acquisition and Integration Costs	1,138	0	3,415	0
Restructuring Charges	50,432	48,371	129,686	128,715	$ 372,679
Intangible impairments	0	0	0	23,000
(Gain) loss on disposal/write-down of property, plant and equipment, net (including real estate)	(935)	(75,840)	(134,321)	(78,170)
Other (income) expense, net, excluding our share of losses (gains) from our unconsolidated joint ventures	(21,517)	81,190	(209,001)	59,398
Stock-based compensation expense	12,644	8,065	45,913	32,056
COVID-19 Costs	0	0	0	9,285
Our share of Adjusted EBITDA reconciling items from our unconsolidated joint ventures	1,252	175	3,340	450
Adjusted EBITDA	$ 417,769	$ 376,012	$ 1,203,965	$ 1,101,473

Segment Information - Revenues

Segment Information - Revenues by Product and Service Lines by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total Revenues	$ 1,130,148	$ 1,036,647	$ 3,331,944	$ 3,087,617
GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	995,577	921,773	2,955,803	2,755,294
GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	88,587	72,814	236,672	206,939
CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	45,984	42,060	139,469	125,384
Records management
Segment Reporting Information [Line Items]
Total Revenues	797,512	737,902	2,376,461	2,194,442
Records management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	767,059	712,182	2,285,000	2,118,767
Records management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Records management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	30,453	25,720	91,461	75,675
Data management
Segment Reporting Information [Line Items]
Total Revenues	130,792	138,276	399,922	416,802
Data management | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	115,261	121,936	351,914	367,093
Data management | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data management | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	15,531	16,340	48,008	49,709
Information destruction
Segment Reporting Information [Line Items]
Total Revenues	113,257	87,655	318,889	269,434
Information destruction | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	113,257	87,655	318,889	269,434
Information destruction | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Information destruction | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data Center(1)
Segment Reporting Information [Line Items]
Total Revenues	88,587	72,814	236,672	206,939
Data Center(1) | GLOBAL RIM BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	0	0	0	0
Data Center(1) | GLOBAL DATA CENTER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	88,587	72,814	236,672	206,939
Data Center(1) | CORPORATE AND OTHER BUSINESS
Segment Reporting Information [Line Items]
Total Revenues	$ 0	$ 0	$ 0	$ 0

Related Parties - (Details)

Related Parties - (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Frankfurt JV
Related Party Transaction [Line Items]
Revenue	$ 1,200		$ 3,100
Makespace
Related Party Transaction [Line Items]
Revenue	$ 9,300	$ 8,400	$ 24,900	$ 22,300

Project Summit - Additional Inf

Project Summit - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	24 Months Ended	27 Months Ended
	Oct. 31, 2019USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Dec. 31, 2021employee
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 50,432	$ 48,371	$ 129,686	$ 128,715		$ 372,679
Project Summit costs
Restructuring Cost and Reserve [Line Items]
Planned workforce reductions		95.00%		95.00%			95.00%
Restructuring Charges	$ 450,000			$ 129,686		$ 194,396
Forecast | Project Summit costs
Restructuring Cost and Reserve [Line Items]
Percentage of positions eliminated								45.00%
Managerial and administrative workforce | employee								700

Project Summit - Restructuring

Project Summit - Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		24 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 50,432	$ 48,371	$ 129,686	$ 128,715	$ 372,679
GLOBAL RIM BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	11,362	16,183	27,528	37,245	116,568
GLOBAL DATA CENTER BUSINESS
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	1,285	296	2,922	986	4,860
Corporate and Other Business
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	37,785	31,892	99,236	90,484	251,251
Employee severance costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	6,797	13,579	14,526	31,229	82,725
Professional fees and other costs
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 43,635	$ 34,792	$ 115,160	$ 97,486	$ 289,954

Project Summit - Restructurin_2

Project Summit - Restructuring Rollforward (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended	24 Months Ended
	Oct. 31, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Sep. 30, 2021
Restructuring Reserve [Roll Forward]
Amounts accrued		$ 50,432	$ 48,371	$ 129,686	$ 128,715		$ 372,679
Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance				40,053	17,777	$ 17,777
Amounts accrued	$ 450,000			129,686		194,396
Payments				(133,485)		(168,677)
Other, including currency translation adjustments				(939)		(3,443)
Ending balance		35,315		35,315		40,053	35,315
Employee severance costs
Restructuring Reserve [Roll Forward]
Amounts accrued		6,797	13,579	14,526	31,229		82,725
Employee severance costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance				16,278	4,823	4,823
Amounts accrued				14,525		47,349
Payments				(20,771)		(32,455)
Other, including currency translation adjustments				(939)		(3,439)
Ending balance		9,093		9,093		16,278	9,093
Professional fees and other costs
Restructuring Reserve [Roll Forward]
Amounts accrued		43,635	$ 34,792	115,160	97,486		289,954
Professional fees and other costs | Project Summit costs
Restructuring Reserve [Roll Forward]
Beginning balance				23,775	$ 12,954	12,954
Amounts accrued				115,161		147,047
Payments				(112,714)		(136,222)
Other, including currency translation adjustments				0		(4)
Ending balance		$ 26,222		$ 26,222		$ 23,775	$ 26,222